CN109312081B - Composite particles and epoxy resin composition prepared therefrom - Google Patents

Abstract

The present invention provides composite particles useful for curing epoxy resins. More specifically, the composite particles have a porous polymeric core particle, a curing agent and/or curing catalyst for an epoxy resin positioned within the porous polymeric core particle, and a fluoropolymer-containing coating layer surrounding the porous polymeric core particle. Additionally, a curable composition is provided that is a mixture comprising an epoxy resin and the composite particles. The epoxy resin typically does not react until the curable composition is heated to cause the curing agent and/or curing catalyst to be released from the composite particles. Additionally, a cured composition formed from the curable composition is provided.

Description

Composite particles and epoxy resin composition prepared therefrom

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional patent application 62/327220 filed 2016, 4, 25, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

Composite particles comprising a curing agent and/or curing catalyst for epoxy resins, methods of making the composite particles, curable compositions comprising the composite particles and epoxy resins, cured compositions formed from the curable compositions, articles comprising the cured compositions, and methods of making the cured compositions are described.

Background

Curable epoxy compositions are often provided as two-part formulations in which the epoxy resin is separated from the curing agent just prior to forming the cured composition. Once mixed, the curing agent and epoxy resin react rapidly at room temperature or elevated temperature. Such curable epoxy compositions tend to have good storage stability (such as for a year or more), but need to be used soon after mixing the epoxy resin-containing part with the curing agent-containing part. In addition, the two components must be carefully metered together for mixing so that the amounts of epoxy resin and curing agent are appropriate.

The two-component formulation may contain various curing catalysts (e.g., accelerators) that may be used in place of or in combination with the curing agent. These compounds are generally not consumed in the curing reaction, but reduce the activation barrier for the polymerization of the epoxy resin with itself or with the curing agent. Typical curing catalysts include, for example, various imidazole compounds, urea compounds, tertiary amines, and lewis acids.

Some one-component compositions are known in which latent curing agents and/or latent curing catalysts are used. Although no mixing is required, the shelf life of one-component systems is often significantly reduced compared to two-component formulations. The latent curing agent and/or latent curing catalyst is typically a blocked imidazole compound. Shelf life of 6 months or more can be achieved by using a latent curing agent that is thermally activated to form a cured composition. The curing temperature is generally limited by the melting point of the curing agent, which typically exceeds about 150 ℃ or about 170 ℃ of conventional latent curing agents.

Disclosure of Invention

Composite particles and methods of making composite particles are provided. More particularly, the composite particles have a porous polymeric core particle, a curing agent and/or curing catalyst for the epoxy resin positioned within the porous polymeric core particle, and a fluoropolymer-containing coating layer surrounding the porous polymeric core particle. Additionally, a curable composition is provided that is a mixture comprising an epoxy resin and composite particles. The curable composition reacts (i.e., polymerizes) when the curing agent and/or curing catalyst is released from the composite particles and reacts with the epoxy resin. Additionally, a cured composition formed from the curable composition and a method of forming the cured composition are provided.

In a first aspect, a composite particle is provided. The composite particles comprise (a) a porous polymeric core particle, (b) a curing agent and/or curing catalyst for an epoxy resin positioned within the porous polymeric core particle but not covalently bound to the porous polymeric core particle, and (c) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

In a second aspect, a method of making a composite particle is provided. The method includes providing a porous polymeric core particle. The method further includes positioning a curing agent and/or a curing catalyst within the porous polymeric core particle to form a loaded porous polymeric core particle, wherein the curing agent and/or the curing catalyst is not covalently bonded to the porous polymeric core particle. The method also includes providing a coating comprising a fluoropolymer surrounding the loaded porous polymeric core particle.

In a third aspect, a curable composition is provided. The curable composition includes (1) an epoxy resin and (2) composite particles mixed with the epoxy resin. The composite particles comprise (a) a porous polymeric core particle, (b) a curing agent and/or curing catalyst for an epoxy resin positioned within the porous polymeric core particle but not covalently bound to the porous polymeric core particle, and (c) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

In a fourth aspect, a cured composition is provided. The cured composition is the reaction product (i.e., polymerization product) of the curable composition described above.

In a fifth aspect, an article is provided. The article includes a first substrate, a second substrate, and a cured composition positioned between the first substrate and the second substrate (i.e., the cured composition adheres to both the first substrate and the second substrate). The cured composition is the reaction product (i.e., polymerization product) of the curable composition described above.

In a sixth aspect, a method of forming a cured composition is provided. The method includes providing the same curable composition as described above, heating the curable composition to release the curing agent and/or curing catalyst from the composite particles, and curing the epoxy resin.

Drawings

Fig. 1A and 1B are Scanning Electron Microscope (SEM) images of exemplary porous polymeric core particles formed according to preparation example 1. The two SEM images have different magnifications.

Fig. 2 is an SEM image of an exemplary composite particle made according to example 3.

Fig. 3A and 3B are SEM images of exemplary composite particles prepared according to example 4. The two SEM images have different magnifications.

Figure 4 shows Differential Scanning Calorimetry (DSC) plots of heat flow versus temperature for example 9 and comparative example 1.

Detailed Description

The invention provides composite particles and methods of making the composite particles. The composite particles comprise a curing agent and/or a curing catalyst for the epoxy resin. Additionally, curable compositions comprising composite particles and epoxy resins, cured compositions formed from the reaction (i.e., polymerization or curing) of the curable resin compositions, articles comprising the cured compositions, and methods of making the cured compositions are provided. The curable composition is a one-component formulation comprising a mixture of an epoxy resin and composite particles. The composite particles comprise a curing agent and/or a curing catalyst that is releasable from the composite particles when the curable composition is heated above a certain temperature. Once released from the composite particles, the curing agent and/or curing catalyst may react with the epoxy resin to form a cured composition. The curable composition may have excellent storage stability.

As used herein, the term "(meth) acryloyl" refers to the formula CH₂＝C(R¹) A radical of- (CO) -O-, in which R¹Is hydrogen or methyl. The term "(meth) acrylic acid" includes acrylic acid and/or acrylic acid. The term "alkyl (meth) acrylate" includes alkyl acrylates and/or alkyl methacrylates.

As used herein, the terms "polymer," "polymerized," and "polymeric material" are used interchangeably to refer to homopolymers, copolymers, terpolymers, etc.

As used herein, the terms "fluoropolymer" and "fluorinated polymer" are used interchangeably to refer to a polymer having at least one fluorine atom. Fluorinated polymers are typically formed from fluorinated monomers, which are monomers having at least one fluorine atom.

The term "curing agent" refers to a compound that reacts with an epoxy resin. In many embodiments, the curing agent is a nitrogen-containing compound. The curing agent is consumed in the reaction with the epoxy resin and becomes part of the cured composition. The curing agent may be used alone or in combination with a curing catalyst to cure the epoxy resin.

The term "curing catalyst" refers to a compound that reduces the activation barrier for the polymerization of an epoxy resin, accelerates the reaction of a curing agent with an epoxy resin, initiates the polymerization of an epoxy resin, or initiates the reaction of a curing agent with an epoxy resin. In some embodiments, the curing catalyst is not generally consumed in the reaction, and it is generally used in lower amounts than the curing agent. In other embodiments, a curing catalyst is attached to a first end of the cured product. The curing catalyst may be used alone or in combination with a curing agent to cure the epoxy resin.

As used herein, the term "and/or" refers to one or two. For example, the expression "curing agent and/or curing catalyst" refers to only a curing agent, only a curing catalyst, or both a curing agent and a curing catalyst. This expression is equivalent to the expression "curing agent, curing catalyst or mixtures thereof".

The terms "curable composition" and "curable epoxy resin composition" are used interchangeably. Likewise, the terms "cured composition" and "cured epoxy resin composition" are used interchangeably.

In one aspect, a composite particle is provided. The composite particles are used to store a curing agent and/or a curing catalyst in a curable composition comprising an epoxy resin and then deliver the curing agent and/or the curing catalyst. The composite particles comprise 1) a porous polymeric core particle, 2) a curing agent and/or curing catalyst positioned within the porous polymeric core particle but not covalently bonded to the porous polymeric core particle, and 3) a fluoropolymer-containing coating layer surrounding the porous polymeric core particle. When the curable composition is heated, such as at a temperature above room temperature, the curing agent and/or curing catalyst may be released from the composite particle by diffusing out of the porous polymeric core particle through the coating layer. The released curing agent and/or curing catalyst may then react with the epoxy resin, resulting in the formation of a cured composition.

In another aspect, a method of making a composite particle is provided. The method includes providing a porous polymeric core particle. The method further includes positioning a curing agent and/or a curing catalyst within the porous polymeric core particle to form a loaded porous polymeric core particle in which the curing agent and/or the curing catalyst is not covalently bonded to the porous polymeric core particle. The method also includes providing a coating comprising a fluoropolymer surrounding the loaded porous polymeric core particle.

The composite particles have a porous polymeric core particle. The polymer core particle has pores (i.e., voids or free volume) on its outer surface and/or mesochannels into the interior region. In at least some embodiments, the polymeric core particle is hollow on the inside. The terms "porous polymeric core particle" and "polymeric core particle" are used interchangeably.

The curing agent and/or curing catalyst is positioned (i.e., adsorbed or loaded) within the porous polymeric core particle. In other words, the porous polymeric core particles are loaded (i.e., filled) with the curing agent and/or curing catalyst, and the resulting material is interchangeably referred to as "loaded polymeric core particles" and "loaded porous polymeric core particles".

The terms "porous composite particle" and "composite particle" are used interchangeably and refer to a loaded polymeric core particle coated with a fluorinated polymer. Because the composite particles comprise a porous polymeric core particle, the composite particles themselves may be considered to be porous. The composite particles may be considered to be capsules containing the curing agent and/or curing catalyst (i.e., the curing agent and/or curing catalyst is encapsulated within the porous polymeric core particle portion of the composite particles). The capsules comprise a loaded polymeric core particle encapsulated with a coating comprising a fluoropolymer.

Any suitable porous polymeric core particle may be used, but the porous polymeric core particle is typically a crosslinked (meth) acrylate polymeric material. The term "(meth) acrylate polymeric material" refers to a polymeric material formed mainly from monomers having a (meth) acryloyl group as a polymerizable group. At least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt%, or at least 100 wt% of the monomers used to form the (meth) acrylate polymeric material have a polymerizable (meth) acryloyl group. In most embodiments, the crosslinked (meth) acrylate polymeric material is the polymerization product of a monomer composition comprising at least one monomer having a plurality of (i.e., at least two) (meth) acryloyl groups.

The porous polymeric core particles are typically formed from a reaction mixture comprising a first phase and a second phase dispersed (e.g., as droplets) in the first phase, wherein the volume of the first phase is greater than the volume of the second phase. The first phase provides a non-polymeric medium for suspending the second phase as droplets within the reaction mixture. The second phase droplets comprise both a polymerizable monomer composition and a porogen which is poly (propylene glycol). The monomer composition in the second phase droplets typically comprises one or more monomers having a (meth) acryloyl group.

In many embodiments, the porous polymeric core particle comprises the polymerization product of a reaction mixture comprising i) a first phase and ii) a second phase dispersed (e.g., as droplets) in the first phase, wherein the volume of the first phase is greater than the volume of the second phase. The first phase is considered to be a continuous phase and typically does not contain polymerizable compounds. The second phase typically comprises a monomer composition that 1) comprises one or more monomers having a (meth) acryloyl group and 2) poly (propylene glycol). In many embodiments, the monomer composition comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl. Poly (propylene glycol) s typically have a weight average molecular weight of at least 500 daltons (i.e., Da). The poly (propylene glycol) is removed from the polymerization product to provide porous polymeric core particles.

The first phase of the reaction mixture typically comprises 1) water plus a polysaccharide dissolved in the water, or 2) a surfactant plus a polyol compound of formula (II).

HO[-CH₂-CH(OH)-CH₂-O]_x-H

(II)

The variable x in formula (II) is an integer equal to at least 1. The first phase is typically formulated to provide a viscosity and volume suitable for dispersing the second phase as droplets within the first phase. If the viscosity of the first phase is too high, it may be difficult to provide the shear needed to disperse the second phase. However, if the viscosity is too low, it may be difficult to suspend the second phase and/or form polymer core particles that are relatively uniform and well separated from each other.

In some embodiments, the first phase comprises a mixture of water and a polysaccharide dissolved in the water. The polysaccharide may be, for example, water-soluble starch or water-soluble cellulose. Suitable water-soluble starches and water-soluble celluloses often have viscosities in the range of 6 to 10 centipoise at room temperature (i.e., 20 ℃ to 25 ℃) for a 2 wt% aqueous solution. Water-soluble starches are generally prepared by acid hydrolysis of a portion of the starch. Examples of water-soluble starches include, for example, those commercially available from Roquette (lestem, France) under the trade name LYCOAT. Examples of water-soluble celluloses include, but are not limited to, alkyl celluloses (e.g., methyl cellulose, ethyl cellulose, and ethyl methyl cellulose), hydroxyalkyl celluloses (e.g., hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and hydroxyethyl ethyl cellulose), and carboxyalkyl celluloses (e.g., carboxymethyl cellulose).

In these embodiments, the first phase may comprise up to 50 wt.% of the polysaccharide, based on the total weight of the first phase. For example, the first phase may comprise at most 40 wt.%, at most 30 wt.%, at most 25 wt.%, at most 20 wt.%, at most 15 wt.%, or at most 10 wt.% of the polysaccharide. The first phase typically comprises at least 5 wt.%, at least 10 wt.%, or at least 15 wt.% polysaccharide. In some embodiments, the first phase comprises from 5 wt% to 50 wt%, from 5 wt% to 40 wt%, from 10 wt% to 40 wt%, from 5 wt% to 30 wt%, from 10 wt% to 30 wt%, from 5 wt% to 25 wt%, from 10 wt% to 25 wt%, or from 15 wt% to 25 wt% of the polysaccharide, based on the total weight of the first phase. The remainder of the first phase (i.e., the portion of the first phase that is not the polysaccharide) is typically water or primarily water (e.g., at least 90 wt% water, at least 95 wt% water, at least 98 wt% water, or 100 wt% water). Any remaining portion other than water may be an optional organic solvent that is miscible with water.

In some examples, the first phase comprises 5 to 50 wt.% of the polysaccharide and 50 to 95 wt.% of water, 5 to 40 wt.% of the polysaccharide and 60 to 95 wt.% of water, 10 to 40 wt.% of the polysaccharide and 60 to 90 wt.% of water, 5 to 30 wt.% of the polysaccharide and 70 to 95 wt.% of water, 10 to 30 wt.% of the polysaccharide and 70 to 90 wt.% of water, 5 to 25 wt.% of the polysaccharide and 75 to 95 wt.% of water, 10 to 25 wt.% of the polysaccharide and 75 to 90 wt.% of water, or 15 to 25 wt.% of the polysaccharide and 75 to 85 wt.% of water. The various amounts are based on the total weight of the first phase. In many examples, the first phase contains only water and dissolved polysaccharide (i.e., the weight percent of polysaccharide plus the weight percent of water equals 100 wt%). In other examples, the only other material included in the first phase is an optional organic solvent.

If an optional organic solvent is used in the water/polysaccharide first phase, a water-miscible organic solvent is selected. Suitable organic solvents include, for example, alcohols (e.g., methanol, ethanol, n-propanol, or isopropanol) or polyol compounds of formula (II). The amount of the optional organic solvent is generally no greater than 10 wt-%, no greater than 5 wt-%, no greater than 2 wt-%, or no greater than 1 wt-%, based on the total weight of the first phase. In some examples, the first phase is free or substantially free of an optional organic solvent. The term "substantially free" as used herein with respect to the optional organic solvent in the first phase means that the organic solvent is not intentionally added to the first phase, but may be present as an impurity in one of the other components in the first phase. For example, the amount of the optional organic solvent is less than 1 wt%, less than 0.5 wt%, or less than 0.1 wt%, based on the total weight of the first phase.

In other embodiments, the first phase comprises a mixture of the polyol compound of formula (II) and a surfactant, rather than a mixture of water and dissolved polysaccharide. For at least some second phase compositions, using a first phase comprising a polyol compound of formula (II) and a surfactant, polymer core particles having greater porosity (e.g., greater pore content) may be obtained.

Suitable polyol compounds of formula (II) typically have an x value in the range of 1 to 20, in the range of 1 to 16, in the range of 1 to 12, in the range of 1 to 10, in the range of 1 to 6 or in the range of 1 to 4. In many embodiments, the polyol compound of formula (II) is glycerol, wherein the variable x equals 1. Other exemplary polyol compounds of formula (II) are diglycerol (x equal to 2), polyglycerol-3 (x equal to 3), polyglycerol-4 (x equal to 4), or polyglycerol-6 (x equal to 6). Polyglycerol, which may be referred to as a glycerol polymer, is typically a mixture of materials of varying molecular weight (i.e., materials having different values of x). Polyglycerols, diglycerols, and glycerols are commercially available, for example, from suvin Chemical (brussel, Belgium) and Wilshire Technologies (Princeton, NJ, USA).

In the first phase, a surfactant is generally used in combination with the polyol compound of formula (II). The surfactant is typically a nonionic surfactant. Nonionic surfactants generally increase the porosity on the surface of the final polymeric core particle. The first phase is typically free or substantially free of ionic surfactants that can interfere with the polymerization of the monomers in the second phase. As used herein with respect to ionic (i.e., anionic or cationic) surfactants, the term "substantially free" means that the ionic surfactant is not intentionally added to the first phase, but may be present as a trace impurity in one of the other components in the first phase. Any impurities are typically present in an amount of no greater than 0.5 wt.%, no greater than 0.1 wt.%, or no greater than 0.05 wt.%, based on the total weight of the first phase.

Any suitable nonionic surfactant can be used in the first phase. The nonionic surfactant is selected to be soluble in the polyol compound of formula (II). Nonionic surfactants typically have one or more hydroxyl groups or ether linkages (e.g., -CH) in a portion of the molecule₂-O-CH₂-) which can hydrogen bond with other components of the reaction mixture. Suitable nonionic surfactants include, but are not limited to, alkyl glucosides, alkyl glucamides, alkyl polyglycosides, polyethylene glycol alkyl ethers, block copolymers of polyethylene glycol and polypropylene glycol, and polysorbates. Suitable alkylglucidesExamples of glycosides include, but are not limited to, octyl glucoside (also known as octyl- β -D-glucopyranoside) and decyl glucoside (also known as decyl- β -D-glucopyranoside). Examples of suitable alkylglucamides include, but are not limited to, octanoyl-N-methylglucamide, nonanoyl-N-methylglucamide, and decanoyl-N-methylglucamide. These surfactants are available, for example, from Sigma Aldrich (st. louis, MO, USA) or sburpur Chemicals (New Brunswick, NJ, USA). Examples of suitable alkyl polyglycosides include, but are not limited to, those commercially available under the trade name APG (e.g., APG 325) from corning Corporation (Cincinnati, OH, USA) and those commercially available under the trade name TRITON (e.g., TRITON BG-10 and TRITON CG-110) from Dow Chemical (Midland, MI, USA) from Dow Chemical Corporation (michigan). Examples of polyethylene glycol alkyl ethers include, but are not limited to, those commercially available from Sigma Aldrich, saint louis, MO, USA under the trade name BRIJ (e.g., BRIJ 58 and BRIJ 98). Examples of block copolymers of polyethylene glycol and polypropylene glycol include, but are not limited to, those commercially available from BASF (Florham Park, NJ, USA) under the trade name PLURONIC. Examples of polysorbates include, but are not limited to, those commercially available under the trade name TWEEN from Mill Hall (Croda (Mill Hall, PA, USA)) in poa.

When the first phase comprises a mixture of the polyol compound of formula (II) and a surfactant, which is typically a nonionic surfactant, the surfactant can be present in any suitable amount. Typically, the surfactant is present in an amount equal to at least 0.5 wt%, at least 1 wt%, or at least 2 wt%, based on the total weight of the first phase. The surfactant may be present in an amount up to 15 wt-%, up to 12 wt-%, or up to 10 wt-%, based on the total weight of the first phase. For example, the surfactant is typically present in the first phase in an amount in the range of from 0.5 wt% to 15 wt%, in the range of from 1 wt% to 12 wt%, in the range of from 0.5 wt% to 10 wt%, or in the range of from 1 wt% to 10 wt%, based on the total weight of the first phase. The remainder of the first phase (the portion of the first phase that is not a surfactant) is typically a polyol compound of formula (II) or is predominantly a polyol compound of formula (II) (e.g., at least 90 wt.%, at least 95 wt.%, at least 98 wt.%, or 100 wt.% is a polyol compound of formula (II)). Any remaining portion of the polyol that is not of formula (II) may be water or an optional organic solvent that is miscible with the polyol.

In some examples, the first phase may comprise 0.5 wt% to 15 wt% surfactant and 85 wt% to 99.5 wt% compound of formula (II), 1 wt% to 12 wt% surfactant and 88 wt% to 99 wt% compound of formula (II), 0.5 wt% to 10 wt% surfactant and 90 wt% to 99.5 wt% compound of formula (II), or 1 wt% to 10 wt% surfactant and 90 wt% to 99 wt% compound of formula (II). The various amounts are based on the total weight of the first phase. In many examples, the first phase comprises only surfactant and the compound of formula (II) (i.e., the weight percent of surfactant plus polyol compound of formula (II) is 100 wt% of the first phase). In other examples, the only other material contained in the first phase is an optional organic solvent or an optional water.

When the first phase comprises a polyol compound of formula (II) and a surfactant, an optional organic solvent miscible with the polyol compound of formula (II) may be present in the reaction mixture. Suitable organic solvents include, for example, alcohols such as methanol, ethanol, n-propanol or isopropanol. In addition, optional water may be added to the first phase. The amount of any optional water or organic solvent is selected such that the desired viscosity of the first phase can be achieved. The amount of optional water or organic solvent is typically no greater than 10 wt-%, no greater than 5 wt-%, or no greater than 1 wt-%, based on the total weight of the first phase. If higher amounts of water are included, the porosity of the resulting polymeric material may decrease. In some embodiments, the first phase is free or substantially free of optional water or organic solvent. The term "substantially free" as used herein with respect to optional water or organic solvent in the first phase means that water or organic solvent is not intentionally added to the first phase, but may be present as an impurity in one of the other components in the first phase. For example, the amount of optional water or organic solvent is less than 1 wt%, less than 0.5 wt%, or less than 0.1 wt%, based on the total weight of the first phase.

The reaction mixture comprises a second phase dispersed in the first phase. The volume of the first phase is greater than the volume of the second phase. The volume of the first phase is sufficiently large compared to the volume of the second phase so that the second phase can be dispersed in the form of droplets within the first phase. Within each droplet, the monomer composition polymerizes to form a polymerization product. To form polymer particles from the second phase, the volume ratio of the first phase to the second phase is typically at least 2: 1. As the volume ratio increases (e.g., when the ratio is at least 3:1, at least 4:1, or at least 5: 1), polymer particles of relatively uniform size and shape can be formed. However, if the volume ratio is too large, the reaction efficiency decreases (i.e., a smaller amount of polymer core particles is produced). The volume ratio is generally no greater than 25:1, no greater than 20:1, no greater than 15:1, or no greater than 10: 1.

The second phase comprises 1) a monomer composition comprising one or more monomers having at least one (meth) acryloyl group, and 2) poly (propylene glycol) (PPG) having a weight average molecular weight of at least 500 daltons. The weight average molecular weight of the PPG is typically at least 1000 daltons or at least 2000 daltons. The weight average molecular weight may be up to 10,000 daltons or even greater, up to 7,500 daltons, or up to 5,000 daltons. In some embodiments, the weight average molecular weight is in the range of 500 daltons to 10,000 daltons, in the range of 1,000 daltons to 10,000 daltons, or in the range of 1,000 daltons to 5,000 daltons. The PPG serves as a porogen that is partially entrained within the polymerization product as the polymerization product is formed from the monomer composition. Because the PPG has no polymerizable groups, the material can be removed after the polymerized product is formed. Upon removal of the previously entrained PPG, pores (i.e., void volume or free volume) are created. The polymer core particles resulting from the removal of entrained polypropylene glycol are porous. In at least some embodiments, the porous polymeric core particles have a hollow center. The presence of pores or both pores and hollow centers makes the polymeric core particle well suited for the storage and delivery of various curing agents and/or curing catalysts.

The monomer composition within the second phase (i.e., the first monomer composition) comprises various monomers that result in the formation of a porous (meth) acrylate polymeric material. The monomer composition comprises one or more monomers having at least one (meth) acryloyl group. In many embodiments, the (meth) acrylate polymeric material is crosslinked and formed from a monomer composition comprising a monomer having a plurality of (meth) acryloyl groups.

In many embodiments, the monomer composition used to form the porous polymeric core particle comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein the variable q is an integer equal to at least 1. In some embodiments, the variable q is an integer no greater than 30, no greater than 20, no greater than 16, no greater than 12, or no greater than 10 and at least 1, at least 2, or at least 3. Ethylene oxide moiety of monomer (i.e., group- [ CH)₂CH₂-O]_q-) typically has a number average molecular weight of no greater than 1200 daltons, no greater than 1000 daltons, no greater than 800 daltons, no greater than 600 daltons, no greater than 400 daltons, no greater than 200 daltons, or no greater than 100 daltons. Radical R¹Is hydrogen or methyl. The monomer of formula (I) in the second phase is generally immiscible with the first phase.

Suitable first monomers of formula (I) are commercially available from Sartomer (Exton, PA, USA) of Exxon, Pa., under the following trade names: SR206 for ethylene glycol dimethacrylate, SR231 for diethylene glycol dimethacrylate, SR205 for triethylene glycol dimethacrylate, SR206 for tetraethylene glycol dimethacrylate, SR210 and SR210A for polyethylene glycol dimethacrylate, SR259 for polyethylene glycol (200) diacrylate, SR603 (e.g., SR6030P) and SR344 for polyethylene glycol (400) di (meth) acrylate, SR252 and SR610 for polyethylene glycol (600) di (meth) acrylate, and SR740 for polyethylene glycol (1000) dimethacrylate.

In some embodiments, the first monomer of formula (I) is the only monomer in the monomer composition of the second phase. In other embodiments, the first monomer of formula (I) may be used in combination with at least one second monomer. The second monomer has a single ethylenically unsaturated group, which is typically of the formula H₂C＝CR¹(meth) acryloyl group of (CO) -, wherein R¹Is hydrogen or methyl. Suitable second monomers are generally immiscible with the first phase, but miscible or immiscible with the first monomer of formula (I).

Some exemplary second monomers have formula (III).

CH₂＝CR¹-(CO)-O-Y-R²

(III)

In the formula, the group R¹Is hydrogen or methyl. In many embodiments, R¹Is hydrogen. The group Y is a single bond, alkylene, oxyalkylene, or poly (oxyalkylene). Radical R²Is a carbocyclic group or a heterocyclic group. These second monomers of formula (III) tend to be miscible with the first monomer of formula (I) in the second phase, but are not miscible with the first phase.

As used herein, the term "alkylene" refers to a divalent group that is an alkane group and includes straight chain groups, branched chain groups, cyclic groups, bicyclic groups, or combinations thereof. As used herein, the term "oxyalkylene" refers to a divalent group that is an oxo group bonded directly to an alkylene group. As used herein, the term "poly (oxyalkylene)" refers to a divalent group having a plurality of oxyalkylene units. Suitable Y alkylene and oxyalkylene groups typically have 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 3 carbon atoms. The oxyalkylene group is usually an oxyethylene group or an oxypropylene group. Suitable poly (oxyalkylene) groups typically have 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 10 carbon atoms, 2 to 8 carbon atoms, 2 to 6 carbon atoms, or 2 to 4 carbon atoms. The poly (oxyalkylene) is typically a poly (oxyethylene) group, which may be referred to as poly (ethyleneoxy) or poly (ethylene glycol).

Carbocyclic ring R²The groups may have a single ring or may have multiple rings such as fused or bicyclic rings. Each ring may be saturated, partially unsaturated, or unsaturated. Each carbon atom in the ring may be unsubstituted or substituted with an alkyl group. Carbocyclic groups typically have 5 to 12 carbon atoms, 5 to 10 carbon atoms, or 6 to 10 carbon atoms. Examples of carbocyclic groups include, but are not limited to, phenyl, cyclohexyl, cyclopentyl, isobornyl, and the like. Any of these carbocyclic groups may be substituted with an alkyl group having 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

Heterocyclic ring R²The groups may have monocyclic or polycyclic rings such as fused or bicyclic rings. Each ring may be saturated, partially unsaturated, or unsaturated. The heterocyclic group contains at least one heteroatom selected from oxygen, nitrogen or sulfur. The heterocyclic group typically has 3 to 10 carbon atoms and 1 to 3 heteroatoms, 3 to 6 carbon atoms and 1 to 2 heteroatoms, or 3 to 5 carbon atoms and 1 to 2 heteroatoms. Examples of heterocycles include, but are not limited to tetrahydrofurfuryl.

Exemplary monomers of formula (III) for use as the second monomer include, but are not limited to: benzyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate (commercially available from Sartomer under the trade names SR339 and SR 340), isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate (commercially available from Sartomer under the trade names SR285 and SR 203), 3, 5-trimethylcyclohexyl (meth) acrylate (commercially available from Sartomer under the trade names CD421 and CD 421A), and ethoxylated nonylphenol acrylate (commercially available from Sartomer under the trade names SR504, CD613, and CD 612).

Other exemplary second monomers are alkyl (meth) acrylates of formula (IV).

CH₂＝CR¹-(CO)-O-R³

(IV)

In formula (IV), the radical R¹Is hydrogen or methyl. In many embodiments, R¹Is hydrogen. Radical R³Is a straight or branched chain alkyl group having 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. These second monomers tend to be miscible with the first monomer of formula (I) in the second phase, but not the first phase.

Examples of the alkyl (meth) acrylate of formula (IV) include, but are not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, 2-methylbutyl (meth) acrylate, n-hexyl (meth) acrylate, 4-methyl-2-pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-methylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-octyl (meth) acrylate, isononyl (meth) acrylate, isoamyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, n-butyl acrylate, 2-propylheptyl (meth) acrylate, isotridecyl (meth) acrylate, isostearyl (meth) acrylate, octadecyl (meth) acrylate, 2-octyldecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, and heptadecyl (meth) acrylate.

In some embodiments, the only monomers in the monomer composition are the first monomer of formula (I) and the second monomer of formula (III), formula (IV), or both. Any suitable amount of the first monomer and the second monomer can be used. The monomer composition typically comprises from 10 to 90 weight percent of the first monomer and from 10 to 90 weight percent of the second monomer, based on the total weight of monomers in the monomer composition. For example, the second phase can comprise 20 to 80 weight percent of the first monomer and 20 to 80 weight percent of the second monomer, 25 to 75 weight percent of the first monomer and 25 to 75 weight percent of the second monomer, 30 to 70 weight percent of the first monomer and 30 to 70 weight percent of the second monomer, or 40 to 60 weight percent of the first monomer and 40 to 60 weight percent of the second monomer, based on the total weight of monomers in the monomer composition.

Depending on the particular curing agent and/or curing catalyst to be positioned within the polymer core particles, it may be desirable to include at least one hydrophilic second monomer in the monomer composition. The addition of the hydrophilic second monomer tends to make the polymeric core particle more suitable for storing and delivering the hydrophilic curing agent and/or curing catalyst. The hydrophilic second monomers are selected such that they are immiscible with the first phase. These monomers may or may not be miscible with the first monomer of formula (I).

Some exemplary hydrophilic second monomers are hydroxyl-containing monomers of formula (V).

CH₂＝CR¹-(CO)-O-R⁴

(V)

In formula (V), the group R¹Is hydrogen or methyl. In many embodiments, R¹Is hydrogen. Radical R⁴Is substituted by one or more hydroxy groups or formula

-(CH₂CH₂O)_nCH₂CH₂A radical of OH, wherein n is an integer equal to at least 1. The alkyl group typically has 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. The number of hydroxyl groups is generally in the range of 1 to 3. The variable n is typically in the range of 1 to 20, in the range of 1 to 15, in the range of 1 to 10, or in the range of 1 to 5. In many embodiments, the second monomer of formula (V) has a single hydroxyl group.

Exemplary monomers of formula (V) include, but are not limited to, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate (e.g., monomers commercially available under the trade names CD570, CD571, and CD572 from Sartomer (saton, PA, USA)) and glycol mono (meth) acrylate.

Other exemplary hydrophilic second monomers are hydroxyl-containing monomers of formula (VI).

CH₂＝CR¹-(CO)-O-R⁵-O-Ar

(VI)

In the formula (VI), the radical R¹Is hydrogen or methyl. In many embodiments, R¹Is hydrogen. Radical R⁵Is alkylene substituted with at least one hydroxyl group. Suitable alkylene groups typically have 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Alkylene radical R⁵May be substituted with 1 to 3 hydroxyl groups, but is typically substituted with a single hydroxyl group. The group Ar is an aryl group having 6 to 10 carbon atoms. In many embodiments, the Ar group is phenyl. An exemplary monomer of formula (VI) is 2-hydroxy-2-phenoxypropyl (meth) acrylate.

If the second monomer has formula (V) or formula (VI) as the hydroxyl group-containing monomer, the amount of that monomer that can be combined with the first monomer of formula (I) is typically no greater than 2 weight percent, based on the total weight of monomers in the monomer composition. If greater than about 2 weight percent of the second monomer of formula (V) or formula (VI) is used, the resulting polymer core particles tend to have reduced porosity.

The other hydrophilic monomer may be used as the second monomer in an amount greater than the second monomer of formula (V) or (VI) without reducing the porosity of the resulting polymeric core particle. For example, the sulfonyl-containing monomer of formula (VII) or a salt thereof may be included in the monomer composition together with the first monomer of formula (I).

CH₂＝CR¹-(CO)-O-R⁶-SO₃H

(VII)

In formula (VII), the group R¹Is hydrogen or methyl. In many embodiments, R¹Is hydrogen. Radical R⁶Is an alkylene group having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Examples of sulfonyl-containing monomers of formula (VII) include, but are not limited to, sulfoethyl (meth) acrylate (e.g., 2-sulfoethyl methacrylate) and sulfopropyl (meth) acrylate. At some pHThe sulfonyl-containing monomer may be a salt, provided that it is a salt. That is, the monomer may have a negative charge and be associated with a positively charged counterion. Exemplary counterions include, but are not limited to, alkali metal, alkaline earth metal, ammonium ions, and tetraalkylammonium ions.

If the second monomer is a sulfonyl-containing monomer of formula (VII), the monomer composition may comprise up to 20 weight percent of the monomer based on the total weight of monomers in the monomer composition. In some embodiments, the only monomers in the monomer composition are the first monomer of formula (I) and the second monomer of formula (VII). Any suitable amount of the first monomer and the second monomer can be used. The monomer composition typically comprises 80 to 99 weight percent of the first monomer of formula (I) and 1 to 20 weight percent of the second monomer of formula (VII), based on the total weight of monomers in the monomer composition. For example, the monomer composition can comprise 85 to 99 weight percent of the first monomer and 1 to 15 weight percent of the second monomer, 90 to 99 weight percent of the first monomer and 1 to 10 weight percent of the second monomer, and 95 to 99 weight percent of the first monomer and 1 to 5 weight percent of the second monomer, based on the total weight of monomers in the monomer composition.

In other embodiments, the monomer composition comprises a first monomer of formula (I) and two second monomers including sulfonyl-containing monomers, such as those of formula (VII), and hydroxyl-containing monomers, such as those of formula (V) or (VI). When a hydroxyl-containing monomer is combined with a sulfonyl-containing monomer, a greater amount of the hydroxyl-containing monomer can be added to the monomer composition without significantly reducing the porosity of the resulting polymer core particle. That is, the amount of hydroxyl containing monomer can be greater than 2 weight percent based on the weight of monomers in the monomer composition. Such monomer compositions typically comprise 80 to 99 weight percent of a first monomer of formula (I) and 1 to 20 weight percent of a second monomer, wherein the second monomer is a mixture of the sulfonyl-containing monomer of formula (VII) and the hydroxyl-containing monomer of formula (V) or (VI). Up to 50 wt%, up to 40 wt%, up to 20 wt%, or up to 10 wt% of the second monomer may be a hydroxyl-containing monomer.

In other embodiments, the monomer composition comprises a first monomer of formula (I) and two second monomers, including sulfonyl-containing monomers, such as those of formula (VII), and monomers of formula (III). Such monomer compositions typically comprise from 1 to 20% by weight of the monomer of formula (VII) and from 80 to 99% by weight of a mixture of the monomer of formula (I) and the monomer of formula (III). For example, the monomer composition may comprise 1 to 10 weight percent of the monomer of formula (VII) and 90 to 99 weight percent of a mixture of the monomer of formula (I) and the monomer of formula (III), or may comprise 1 to 5 weight percent of the monomer of formula (VII) and 95 to 99 weight percent of a mixture of the monomer of formula (I) and the monomer of formula (III). These compositions may be advantageous in that they may be used to carry hydrophobic or hydrophilic curing agents and/or curing catalysts.

In some more specific examples, the monomer composition can comprise 1 to 20 weight percent of the monomer of formula (VII), 1 to 98 weight percent of the monomer of formula (I), and 1 to 98 weight percent of the monomer of formula (III). In another example, the monomer composition can comprise 1 to 20 weight percent of the monomer of formula (VII), 5 to 95 weight percent of the monomer of formula (I), and 5 to 95 weight percent of the monomer of formula (III). In another example, the monomer composition comprises 1 to 10 weight percent of the monomer of formula (VII), 20 to 80 weight percent of the monomer of formula (I), and 20 to 80 weight percent of the monomer of formula (III). In yet another example, the monomer composition comprises 1 to 10 weight percent of the monomer of formula (VII), 30 to 70 weight percent of the monomer of formula (I), and 30 to 70 weight percent of the monomer of formula (III). In yet another example, the monomer composition comprises 1 to 10 weight percent of the monomer of formula (VII), 40 to 60 weight percent of the monomer of formula (I), and 40 to 60 weight percent of the monomer of formula (III).

In these monomer compositions comprising monomers of formulae (VII), (I), and (III), the amount of monomer of formula (VII) can be used to control the average size of the porous polymeric core particles. For example, when about 5 wt% of the monomer of formula (VII) is included in the monomer composition, the resulting porous polymeric core particles have an average diameter of about 10 microns. When about 1 wt% of the monomer of formula (VII) is included in the monomer composition, the resulting porous polymeric core particles have an average diameter of about 3 microns.

Other exemplary second monomers are carboxyl group-containing monomers having a carboxylic acid group (-COOH) or salts thereof. Examples of such carboxyl group-containing monomers include, but are not limited to, (meth) acrylic acid and carboxyalkyl (meth) acrylates, such as 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, and the like. Under some pH conditions, the carboxyl-containing monomer may be a salt. That is, these monomers may have a negative charge and be associated with a positively charged counterion. Exemplary counterions include, but are not limited to, alkali metal, alkaline earth metal, ammonium ion, and tetraalkylammonium ion.

Other second monomers are quaternary ammonium salts such as, for example, (meth) acrylamidoalkyltrimethylammonium salts (e.g., 3-methacrylamidopropyltrimethylammonium chloride and 3-acrylamidopropyltrimethylammonium chloride) and (meth) acryloyloxyalkyltrimethylammonium salts (e.g., 2-acryloyloxyethyltrimethylammonium chloride, 2-methacryloyloxyethyltrimethylammonium chloride, 3-methacryloyloxy-2-hydroxypropyltrimethylammonium chloride, 3-acryloyloxy-2-hydroxypropyltrimethylammonium chloride, and 2-acryloyloxyethyltrimethylammonium methylsulfate ammonium salt).

In addition to the first monomer of formula (I) or in addition to a mixture of the first monomer of formula (I) and one or more of the second monomers described above, the monomer composition may optionally comprise a third monomer having at least two polymerizable groups. The polymerizable group is typically a (meth) acryloyl group. In many embodiments, the third monomer has two or three (meth) acryloyl groups. The third monomer is typically immiscible with the first phase and may or may not be miscible with the first monomer of formula (I).

Some third monomers have hydroxyl groups. Such monomers may be used as cross-linkers, for example the first monomer of formula (I), but may provide a polymer core particle with increased hydrophilicity characteristics. This may be desirable for storage and delivery of the hydrophilic curing agent and/or curing catalyst. An exemplary hydroxyl-containing third monomer is glycerol di (meth) acrylate.

Some third monomers are selected to have at least three polymerizable groups. Such a third monomer may be added to provide greater rigidity to the resulting polymeric core particle. The addition of these third monomers tends to minimize swelling of the polymer core particles. Suitable third monomers include, but are not limited to, ethoxylated trimethylolpropane tri (meth) acrylate such as ethoxylated (15) trimethylolpropane triacrylate (commercially available from Sartomer under the trade designation SR 9035) and ethoxylated (20) trimethylolpropane triacrylate (commercially available from Sartomer under the trade designation SR 415); propoxylated trimethylolpropane tri (meth) acrylate such as propoxylated (3) trimethylolpropane triacrylate (commercially available from Sartomer under the trade designation SR 492) and propoxylated (6) trimethylolpropane triacrylate (commercially available from Sartomer under the trade designation CD 501); tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate such as tris (2-hydroxyethyl) isocyanurate triacrylate (commercially available from Sartomer company (Sartomer) under the trade names SR368 and SR 368D); and propoxylated glyceryl tri (meth) acrylates such as propoxylated glyceryl (3) triacrylate (commercially available from Sartomer, inc (Sartomer) under the trade names SR9020 and SR9020 HP).

When the third monomer is present in the monomer composition, any suitable amount can be used. The third monomer is typically used in an amount of up to 20 weight percent based on the total weight of monomers in the monomer composition. In some embodiments, the amount of the third monomer is at most 15 weight percent, at most 10 weight percent, or at most 5 weight percent.

The monomer composition typically comprises 10 to 100 weight percent of the first monomer, 0 to 90 weight percent of the second monomer, and 0 to 20 weight percent of the third monomer, based on the total weight of monomers in the monomer composition. For example, the monomer composition can comprise 10 to 90 weight percent of the first monomer, 10 to 90 weight percent of the second monomer, and 0 to 20 weight percent of the third monomer. The monomer composition can include 10 to 89 weight percent of the first monomer, 10 to 89 weight percent of the second monomer, and 1 to 20 weight percent of the third monomer, based on the total weight of the monomer composition.

In addition to the monomer composition, the second phase also includes poly (propylene glycol), which acts as a porogen. The poly (propylene glycol) is soluble in the monomer composition in the second phase, but is dispersible in the first phase. In other words, the poly (propylene glycol) is fully miscible with the second phase and partially miscible with the first phase. The poly (propylene glycol) is removed after polymerization of the monomer composition to provide pores (e.g., void volume or free volume) in the polymer core particle. The poly (propylene glycol) does not have any polymerizable groups (i.e., it is not a monomer) and, generally, is not covalently attached to the polymer core particles formed within the second phase. It is believed that some of the poly (propylene glycol) may be entrained within the polymerized product. Removal of entrained poly (propylene glycol) can result in the formation of hollow polymeric core particles. It is also believed that some of the poly (propylene glycol) may be located at the interface between the first and second phases because the polymerization product is formed in the second phase. The presence of poly (propylene glycol) at the surface of the formed polymeric product can result in the formation of polymer core particles having surface porosity. Surface porosity can be seen from electron micrographs of polymer core particles such as in fig. 1A and 1B.

Poly (propylene glycol) of any suitable molecular weight may be used as a porogen. The molecular weight can affect the size of the pores formed in the polymer core particle. That is, the pore size tends to increase with the molecular weight of the poly (propylene glycol). The weight average molecular weight is typically at least 500 daltons, at least 800 daltons, or at least 1000 daltons. The poly (propylene glycol) can have a weight average molecular weight of up to 10,000 daltons or greater. For ease of use, poly (propylene glycol) is typically selected to be liquid at room temperature. Poly (propylene glycol) s having a weight average molecular weight of up to about 4000 daltons or 5000 daltons tend to be liquids at room temperature. Poly (propylene glycol) that is not liquid at room temperature may be used if it is initially dissolved in a suitable organic solvent such as an alcohol (e.g., ethanol, n-propanol, or isopropanol). The weight average molecular weight of the poly (propylene glycol) is typically in the range of 500 daltons to 10,000 daltons, in the range of 1000 daltons to 8000 daltons, in the range of 1000 daltons to 5000 daltons, in the range of 1000 daltons to 4000 daltons.

The second phase may comprise up to 50% by weight of poly (propylene glycol). If higher amounts of poly (propylene glycol) are used, the amount of monomer composition contained in the second phase may not be sufficient to form uniformly shaped polymer core particles. In many embodiments, the second phase may comprise up to 45 wt%, up to 40 wt%, up to 35 wt%, up to 30 wt%, or up to 25 wt% of poly (propylene glycol), based on the total weight of the second phase. The second phase typically comprises at least 5% by weight of poly (propylene glycol). If a smaller amount of poly (propylene glycol) is used, the porosity of the resulting polymer core particle may be insufficient. That is, the void volume of the polymer core particles may be insufficient to load and deliver an effective amount of curing agent and/or curing catalyst. The second phase may typically comprise at least 10 wt%, at least 15 wt%, or at least 20 wt% poly (propylene glycol). In some embodiments, the second phase comprises 5 to 50, 10 to 40, 10 to 30, 20 to 50, 20 to 40, or 25 to 35 weight percent of poly (propylene glycol), based on the total weight of the second phase.

In some embodiments, the second phase comprises 50 to 90 weight percent of the monomer composition and 10 to 50 weight percent of poly (propylene glycol), 60 to 90 weight percent of the monomer composition and 10 to 40 weight percent of poly (propylene glycol), 50 to 80 weight percent of the monomer composition and 20 to 50 weight percent of poly (propylene glycol), or 60 to 80 weight percent of the monomer composition and 20 to 40 weight percent of poly (propylene glycol), based on the total weight of the second phase.

In addition to the monomer composition and poly (propylene glycol), the second phase typically also contains an initiator for free radical polymerization of the monomer composition. Any suitable initiator known in the art may be used. The initiator may be a thermal initiator, a photoinitiator, or both. The particular initiator used is generally selected based on its solubility in the second phase. The initiator is typically used at a concentration of 0.1 to 5 wt.%, 0.1 to 3 wt.%, 0.1 to 2 wt.%, or 0.1 to 1 wt.%, based on the weight of monomers in the monomer composition.

When a thermal initiator is added to the reaction mixture, the polymer core particles can be formed at room temperature (i.e., 20 ℃ to 25 ℃) or at elevated temperatures. The temperature required for the polymerization reaction generally depends on the particular thermal initiator used. Examples of thermal initiators include organic peroxides and azo compounds.

When a photoinitiator is added to the reaction mixture, the polymeric core particles may be formed by applying actinic radiation. Suitable actinic radiation includes electromagnetic radiation in the infrared region, the visible region, the ultraviolet region, or combinations thereof.

Examples of photoinitiators suitable for use in the ultraviolet region include, but are not limited to, benzoin alkyl ethers (e.g., benzoin methyl ether and substituted benzoin alkyl ethers such as 4,4' -dimethoxybenzoin), phenones (e.g., substituted acetophenones such as 2, 2-dimethoxy-2-phenylacetophenone and substituted alpha-ketols such as 2-methyl-2-hydroxypropiophenone), phosphine oxides, polymeric photoinitiators, and the like.

Commercially available photoinitiators include, but are not limited to, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (e.g., commercially available under the trade designation IRGACURE 1173 from BASF, Florham Park, NJ, USA), a mixture of 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (e.g., commercially available under the trade designation IRGACURE 4265 from BASF), 2-dimethoxy-1, 2-diphenylethan-1-one (e.g., commercially available under the trade designation IRGACURE 651 from BASF), bis (2, 6-dimethoxybenzoyl) -2, mixtures of 4, 4-trimethyl-pentylphosphine oxide and 1-hydroxy-cyclohexyl-phenyl-ketone (e.g., commercially available from BASF under the trade designation IRGACURE 1800), mixtures of bis (2, 6-dimethoxybenzoyl) -2,4, 4-trimethyl-pentylphosphine oxide (e.g., commercially available from BASF under the trade designation IRGACURE 1700), 2-methyl-1 [4- (methylthio) phenyl ] -2-morpholinopropan-1-one (e.g., commercially available from BASF under the trade designation IRGACURE 907), 1-hydroxy-cyclohexyl-phenyl-ketone (e.g., commercially available from BASF under the trade designation IRGACURE 184), 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) Phenyl ] -1-butanone (e.g., commercially available from BASF under the trade name IRGACURE 369), bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (e.g., commercially available from BASF under the trade name IRGACURE 819), ethyl 2,4, 6-trimethylbenzoyl diphenylphosphinite (e.g., commercially available from BASF under the trade name IRGACURE TPO-L), and 2,4, 6-trimethylbenzoyl diphenylphosphine oxide (e.g., commercially available from BASF under the trade name IRGACURE TPO).

The reaction mixture typically comprises at least 5% by weight of the second phase (dispersed phase) and at most 95% by weight of the first phase (continuous phase). In some embodiments, the reaction mixture comprises from 5 wt% to 40 wt% of the second phase and from 60 wt% to 95 wt% of the first phase, from 5 wt% to 30 wt% of the second phase and from 70 wt% to 95 wt% of the first phase, from 10 wt% to 30 wt% of the second phase and from 70 wt% to 90 wt% of the first phase, or from 5 wt% to 20 wt% of the second phase and from 80 wt% to 95 wt% of the first phase. The weight percentages are based on the total weight of the reaction mixture.

To prepare the polymeric core particles, droplets of the second phase are formed in the first phase. The components of the second phase are typically mixed together prior to addition to the first phase. For example, the monomer composition, initiator, and poly (propylene glycol) may be blended together, and then this blended composition, which is the second phase, is added to the first phase. The resulting reaction mixture is typically mixed under high shear to form a microemulsion. The size of the dispersed second phase droplets can be controlled by the amount of shear, mixing rate, and composition. The size of the droplets can be determined by placing a sample of the mixture under an optical microscope prior to polymerization. Although any desired droplet size may be used, the average droplet diameter is often less than 200 microns, less than 100 microns, less than 50 microns, less than 25 microns, less than 10 microns, or less than 5 microns. For example, the average droplet diameter can be in a range of 1 micron to 200 microns, 1 micron to 100 microns, 5 microns to 50 microns, 5 microns to 25 microns, or 5 microns to 10 microns.

If a photoinitiator is used, the reaction mixture is often spread on a non-reactive surface to a thickness that is penetrable by the desired actinic radiation. The reaction mixture was spread using a method that did not cause coalescence of the droplets. For example, an extrusion process may be used to form the reaction mixture. Typically, the actinic radiation is in the ultraviolet region of the electromagnetic spectrum. If the ultraviolet radiation is applied only from the top surface of the layer of reaction mixture, the thickness of the layer may be up to about 10 millimeters. The thickness may be greater, such as up to about 20 millimeters, if the reactive mixture layer is exposed to ultraviolet radiation from both the top and bottom surfaces. The reaction mixture is subjected to actinic radiation for a time sufficient to react the monomer composition and form the polymeric core particles. Depending on the intensity of the actinic radiation source and the thickness of the reaction mixture layer, the reaction mixture layer is usually polymerized within 5 minutes, within 10 minutes, within 20 minutes, within 30 minutes, within 45 minutes or within 1 hour.

If a thermal initiator is used, the droplets may be polymerized while continuing to mix the reaction mixture. Alternatively, the reaction mixture may be spread to any desired thickness on a non-reactive surface. The layer of reaction mixture may be heated from the top surface, the bottom surface, or from both the top surface and the bottom surface to form the polymeric core particles. The thickness is typically selected to be equivalent to that used when the photoinitiator is used in combination with actinic radiation, such as ultraviolet radiation.

In many embodiments, photoinitiators are preferred over thermal initiators because lower temperatures can be used for polymerization. That is, actinic radiation, such as ultraviolet radiation, can be used to minimize degradation of various components of the reaction mixture that may be sensitive to the temperatures required for use with thermal initiators. In addition, the temperatures typically associated with the use of thermal initiators can undesirably alter the solubility of the various components of the reaction mixture between the first phase and the dispersed second phase.

During the polymerization reaction, the monomer composition reacts within the dispersed second phase droplets suspended in the first phase. As the polymerization reaction continues, the poly (propylene glycol) contained in the second phase is partially entrained within the polymerized product. While it is possible that some portion of the poly (propylene glycol) may be covalently attached to the polymerization product by a chain transfer reaction, it is preferred that the poly (propylene glycol) is not bonded to the polymerization product. The polymerization product is in the form of particles. In some embodiments, the particles are polymeric beads having a relatively uniform size and shape.

After the polymeric product (i.e., the polymer core particles comprising entrained poly (propylene glycol)) is formed, the polymeric product can be separated from the first phase. Any suitable separation method may be used. For example, water is typically added to reduce the viscosity of the first phase. The particles of the polymerization product can be separated by decanting, filtering or centrifuging. The particles of the polymerization product can be further washed by suspending them in water and collecting them again by decanting, filtering, centrifuging or drying.

The particles of the polymerization product may then be subjected to one or more washing steps to remove the poly (propylene glycol) porogen. Suitable solvents for removing poly (propylene glycol) include, for example, acetone, methyl ethyl ketone, toluene, and alcohols such as ethanol, n-propanol, or isopropanol. In other words, solvent extraction can be used to remove entrained poly (propylene glycol) from the polymerization product. Pores are created where the poly (propylene glycol) previously resided.

In various embodiments, the resulting porous polymeric core particles (polymerization product after removal of the poly (propylene glycol) porogen) have an average diameter of less than 200 microns, less than 100 microns, less than 50 microns, less than 25 microns, less than 10 microns, or less than 5 microns. For example, the porous polymeric core particles may have an average diameter in a range of 1 micron to 200 microns, 1 micron to 100 microns, 5 microns to 50 microns, 5 microns to 25 microns, or 5 microns to 10 microns.

The polymeric core particle typically has a plurality of pores distributed over the surface of the particle, as can be seen in fig. 1A and 1B. Based on the diameter of the particles and the size of the pores, the polymer core particles can be described as microparticles (average diameter typically in the range of 1 to 200 microns, in the range of 1 to 100 microns, or in the range of 1 to 50 microns) and nano-porous (pores having a size in the nanometer range, such as in the range of 1 to 200 nanometers, in the range of 10 to 200 nanometers, in the range of 20 to 200 nanometers, or in the range of 50 to 200 nanometers). In some embodiments, in addition to having a plurality of pores distributed on the surface of the particle, the polymer core particle is also hollow. As used herein, the term "hollow" refers to a polymeric core particle having a polymeric exterior surrounding an interior region (cavity or core) that is non-polymeric.

Once formed, the porous polymeric core particle or hollow and porous polymeric core particle is well suited for storing and delivering a curing agent and/or curing catalyst. The curing agent and/or curing catalyst is positioned or located within the porous polymeric core particle. The curing agent and/or curing catalyst is not covalently bonded to the polymer core particle in the loaded polymer core particle or in the final composite particle. The composite particles include a loaded polymeric core particle and a fluorinated polymer coating surrounding the loaded polymeric core particle. Under suitable conditions, the curing agent and/or curing catalyst may be released (i.e., delivered) from the composite particle. When the composite particles comprise a curing agent, the released curing agent may react with the epoxy resin to form a cured composition. That is, the curing agent is consumed in the reaction with the epoxy resin and becomes part of the chemical structure of the cured composition (e.g., cured epoxy resin). When the composite particles comprise a curing catalyst, the released curing catalyst may catalyze, accelerate or initiate the self-polymerization of the epoxy resin and/or may catalyze, accelerate or initiate the reaction of the curing agent with the epoxy resin. In some embodiments, both the curing agent and the curing catalyst are loaded within the porous polymeric core particle. In other embodiments, the curing catalyst is loaded only within the porous polymeric core particle. In other embodiments, the curing agent is loaded only into the porous polymeric core particles.

If all of the monomers in the monomer composition used to form the porous polymeric core particle are hydrophobic, the resulting particle tends to be hydrophobic (i.e., hydrophobic polymeric core particle) and can accept (e.g., be loaded with) a hydrophobic curing agent and/or curing catalyst. However, if some of the monomers in the monomer composition are hydrophilic, the polymeric core particles tend to have hydrophilic characteristics (i.e., hydrophilic polymeric core particles) sufficient to accept a hydrophilic curing agent and/or curing catalyst. Additionally, if the monomer composition comprises a mixture of both hydrophobic and hydrophilic monomers, the polymeric core particles tend to have hydrophobic and hydrophilic characteristics sufficient to accept both a hydrophobic curing agent and/or curing catalyst and a hydrophilic curing agent and/or curing catalyst. In some embodiments, it may be desirable for the polymeric core particle to have both hydrophobic and hydrophilic properties.

The curing agent is typically a nitrogen-containing compound, although any suitable curing agent may be used, such as thiol compounds and anhydride compounds. Some curing agents have at least two formulas-NR⁷A group of H, wherein R⁷Is hydrogen, alkyl, aryl or alkaryl. Suitable alkyl groups typically have 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. The alkyl group can be cyclic, branched, linear, or combinations thereof. Suitable aryl groups typically have 6 to 12 carbon atoms, such as phenyl or biphenyl groups. Suitable alkaryl groups may be alkyl substituted by aryl or aryl substituted by alkyl. The same aryl and alkyl groups discussed above can be used in the alkylaryl group. In most embodiments, R⁷Is hydrogen or alkyl.

When the curing agent diffuses from the composite particle into the epoxy resin, the primary and/or secondary amino groups of the curing agent react with the oxirane groups of the epoxy resin. This reaction opens the ethylene oxide groups and covalently bonds the curing agent to the epoxy resin. The reaction results in the formation of-OCH₂-CH₂-NR⁷A divalent group of (A) wherein R is⁷As defined above.

The curing agent and/or curing catalyst minus the at least two amino groups (i.e., the portion of the curing agent that is not an amino group) can be any suitable aromatic group, aliphatic group, or combination thereof. Some amine curing agents have formula (VIII), with the additional limitation that at least two primary amino groups, at least two secondary amino groups, or at least one primary amino group and at least one secondary amino group are present.

Each R⁷The groups are independently hydrogen, alkyl, aryl or alkaryl as defined above. Each R⁸Independently an alkylene group, a heteroalkylene group, or a combination thereof. Suitable alkylene groups typically have 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Suitable heteroalkylene groups have at least one oxo, thioxo, or-NH-group positioned between two alkylene groups. Suitable heteroalkylene groups typically have 2 to 50 carbon atoms, 2 to 40 carbon atoms, 2 to 30 carbon atoms, 2 to 20 carbon atoms, or 2 to 10 carbon atoms, and up to 20 heteroatoms, up to 16 heteroatoms, up to 12 heteroatoms, or up to 10 heteroatoms. The heteroatom is typically an oxo group. The variable m is an integer equal to at least 1 and may be at most 10 or higher, at most 5, at most 4, or at most 3.

Some amine curing agents may have R selected from alkylene groups⁸A group. Examples include, but are not limited to, ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, dipropylenetriamine, tetraethylenepentamine, hexamethylenediamine, 2-methyl-1, 5-pentamethylenediamine, 1-amino-3-aminomethyl-3, 3, 5-trimethylcyclohexane (also known as isophoronediamine), 1, 3-diaminomethylcyclohexane, 1, 10-diaminodecane, 1, 12-diaminododecene, and the like.

Other amine curing agents may have R selected from heteroalkylene groups such as heteroalkylene with oxygen heteroatoms⁸A group. For example, the curing agent may be a compound such as aminoethylpiperazine, 4,7, 10-trioxatridecane-1, 13-diamine (TTD) (commercially available from TCI America in Portland, OR, USA, Portland, Oreg.), OR a poly (oxyalkylene) diamine (also known as a polyether diamine), such as poly (ethyleneoxy) diamine, and poly (ethyleneoxy) diamine,Poly (propyleneoxy) diamine or copolymers thereof. Commercially available polyether diamines are commercially available under The trade designation JEFFAMINE from Hunsman Corporation (The Woodlands, TX, USA) of Wulanded, Texas.

Other amine curing agents can be formed by reacting a polyamine (i.e., a polyamine refers to an amine having at least two amino groups selected from primary and/or secondary amino groups) with another reactant to form an amine-containing adduct having at least two primary and/or secondary amino groups. For example, a polyamine can be reacted with an epoxy resin to form an adduct having at least two amino groups. If the reaction of the polydiamine with the dicarboxylic acid occurs at a diamine to dicarboxylic acid molar ratio of greater than or equal to 2:1, a polyamidoamine having two amino groups can be formed. As another example, if a polydiamine is reacted with an epoxy resin having two glycidyl groups at a diamine to epoxy molar ratio of greater than or equal to 2:1, an amine-containing adduct having two amino groups can be formed. Such polyamidoamines can be prepared, for example, as described in U.S. Pat. No. 5,629,380(Baldwin et al). A molar excess of the polydiamine is typically used such that the curing agent includes both amine-containing adducts and free (unreacted) polydiamine. For example, the molar ratio of diamine to epoxy resin having two glycidyl groups can be greater than 2.5:1, greater than 3:1, greater than 3.5:1, or greater than 4: 1.

The curing agent may also be one or more aromatic rings substituted with multiple amino groups or with amino-containing groups. Such curing agents include, but are not limited to, xylylenediamine (e.g., m-xylylenediamine) or similar compounds. For example, one such curing agent is commercially available under The trade name ANCAMINE (e.g., ANCAMINE 2609) from Air Chemicals ltd, arlondon, PA, USA and is commercially available under The trade name ARADUR 2965 from Huntsman Corporation (The Woodlands, TX, USA). This particular curing agent is based on m-xylylenediamine. Another exemplary curing agent is 4,4' -diaminodiphenyl sulfone (DDS), which is commercially available as ARADUR 9964-1 from Huntsman Corporation.

Other curing agents also include hydrazine, hydrazide or derivatives thereof (e.g., aminodihydrazide, adipic acid dihydrazide, and isophthaloyl dihydrazide), guanidine or derivatives thereof, and Dicyandiamide (DICY) or derivatives thereof.

Instead of or in addition to curing agents such as those described above, the porous polymeric core particles may be loaded with a curing catalyst. These curing catalyst compounds may be accelerators for curing agents such as those listed, may be catalysts for the self-polymerization of epoxy resins or for the reaction of epoxy resins with curing agents, or may be initiators for the self-polymerization of epoxy resins for the reaction of epoxy resins with curing agents.

Some curing catalysts are phenols substituted with tertiary amino groups, which may have formula (IX).

In formula (IX), each radical R⁹Independently an alkyl group. The variable v is an integer equal to 2 or 3. Radical R¹⁰Is hydrogen or alkyl. Is suitable for R⁹And R¹⁰The alkyl group of (a) typically has 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. An exemplary auxiliary curing agent of formula (IX) is tris-2, 4,6- (dimethylaminomethyl) phenol, which is commercially available under the trade designation ANCAMINE K54 from Air Products and Chemicals, Inc., Allentown, PA, USA, of Allentown, Pa. These compounds generally accelerate the curing agents discussed above.

Another class of cure catalysts are substituted ureas, such as disubstituted ureas. Examples include, but are not limited to, 4' -methylenebis (phenyldimethyl) urea, toluenediisocyanate urea, 3- (4-chlorophenyl) -1, 1-dimethylurea, and various compounds commercially available under the trade name OMICURE (e.g., OMICURE U-35 (which is a cycloaliphatic diurea), U-52, and U-52M) from CVC Thermoset specialty materials, CVC Thermoset Specialties.

Another class of curing catalysts are various sulfonic acid compounds and salts thereof, such as those commercially available under the trade name NACURE from King Industries, ltd, Norwalk, CT, USA.

Other curing catalysts are imidazoles or their salts or imidazolines or their salts. The first type of these compounds can react with epoxy resins at room temperature. The second type of these compounds can be reacted with the epoxy resin after heating above its melting point (e.g., above 150 ℃, above 170 ℃, or above 200 ℃). The second type of compound may be referred to as a "latent curing agent" or a "blocked curing agent".

The first type of imidazole compounds (i.e., those that can react below their melting point) are typically substituted at the 1-or 2-position of the imidazole ring. In epoxy systems, imidazole compounds of this type are useful as accelerators or catalysts for other curing agents, and also as curing catalysts for epoxy resins. Examples of those useful as catalysts or promoters include: 2-methyl-imidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1, 2-dimethylimidazole, 2-heptadecylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenyl-imidazole, and 2-phenyl-4, 5-dihydroxymethylimidazole (commercially available under the trade name CUREZOL 2PZ-S from Air Products and Chemicals, Inc.).

The second type of imidazole compounds (i.e., those capable of reacting above their melting point) are commercially available from Air Products and Chemicals, Inc, under the tradenames curozol 2MA-AZINE (which is 2, 4-diamino-6 (2 '-methylimidazolyl- (1')) ethyl-s-triazine) and curozol 2MA-OK (which is 2, 4-diamino-6 (2 '-methylimidazolyl- (1') (ethyl-s-triazine isocyanurate adduct)) and ARADUR 3123 (which is 1- ((2-methyl-1H-imidazol-1-yl) methyl) naphthalen-2-ol) from Huntsman Corporation, Huntsman Corporation. Other imidazole compounds are metal imidazole salts such as those described in U.S. Pat. No. 4,948,449 (Talbutton et al).

Others suitable as curing catalysts for epoxy resinsThe compound is a lewis acid. Exemplary Lewis acids include, but are not limited to, boron trifluoride (BF)₃) Boron trichloride (BCl)₃) Zinc chloride (ZnCl)₂) Tin chloride (SnCl)₄) Antimony pentachloride (SbCl)₅) Antimony pentafluoride (SbF)₅) Iron chloride (FeCl)₃) Aluminum trichloride (AlCl)₃) Arsenic pentafluoride (AsF)₅) And phosphorus Pentafluoride (PF)₅). Due to their high reactivity, lewis acids are often complexed with nitrogen-containing compounds and/or hydroxyl-containing compounds. The complex is typically liquid at room temperature (e.g., 20 ℃ to 25 ℃); the use of lewis acids as liquids is facilitated because they can be easily incorporated into the porous polymeric core particles to form the loaded polymeric core particles. The molar ratio of lewis acid to complexing agent is typically about 1:1, but may be higher depending on the particular lewis acid and the particular complexing agent. Methods for preparing Lewis acid complexes are described, for example, in U.S. Pat. Nos. 3,565,861(White et al), 4,503,161(Korbel et al), 4,503,211(Robins), and 5,731,369 (Mahoney).

Suitable nitrogen-containing compounds which can be complexed with Lewis acids are alkylamines, heteroalkylamines, arylamines, aralkylamines, alkylarylamines, alkylenediamines, arylenediamines and alkylaryldiamines. Suitable alkylamines typically have alkyl groups having 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Exemplary alkylamines include, but are not limited to, methylamine, ethylamine, isopropylamine, n-propylamine, n-butylamine, isobutylamine, tert-butylamine, n-hexylamine, isohexylamine, cyclohexylamine, laurylamine, and stearylamine. Suitable heteroalkylamines typically have from 2 to 20 carbon atoms and from 1 to 10 oxygen heteroatoms. Exemplary heteroalkylamines include, but are not limited to, methoxyethylamine, ethoxyethylamine, and ethoxypropylamine. Suitable aralkyl (i.e., alkyl substituted with aryl) amines typically have an alkyl group having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms and a phenyl group. Examples include, but are not limited to, benzylamine and phenethylamine. Suitable arylamines typically have an aryl group, such as phenyl or naphthyl. Examples are aniline or 1-naphthylamine. Suitable alkaryl (i.e., aryl substituted with an alkyl) amines typically have a phenyl ring substituted with 1 to 5 alkyl groups (e.g., 1 to 4 alkyl groups, 1 to 3 alkyl groups, or 1 to 2 alkyl groups), each alkyl group having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Examples include, but are not limited to, 2-methylaniline, 2-isopropylaniline, 2-propylaniline, 2-hexylaniline, 2, 4-dimethylaniline, 2, 5-dimethylaniline, 2, 6-diethylaniline, N-2, 6-triethylaniline, N-methyl-2, 6-diethylaniline, N, N, 2-trimethylaniline, N, N,2, 6-tetramethylaniline, 2, 6-dipropylaniline, 2, 6-diisobutylalniline, 2, 6-di-N-butylaniline, 2, 6-di-N-pentylaniline, N, N-diethyl-2-N-butylaniline, 2,3,4,5, 6-pentamethylaniline, N-propylaniline, N-hexylaniline, 2, 4-dimethylaniline, 2, 6-methylaniline, 2, 6-di-N-butylaniline, 2,3,4,5, 6-pentamethylaniline, N-propylaniline, 2-hexylaniline, 2, 6-methylaniline, 2, 6-butylaniline, 2,6, 2,6, 2, and the like, N-hexylaniline, N-sec-butylaniline and 2-ethyl-6-sec-butylaniline. Suitable alkylenediamines typically have an alkylene group of 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms (i.e., a divalent group of an alkane). Exemplary alkylenediamines include, but are not limited to, methylenediamine, ethylenediamine, propylenediamine, and butylenediamine. Exemplary arylene diamines are typically phenylene diamines such as m-phenylene diamine, o-phenylene diamine, and p-phenylene diamine. Suitable alkylenediamines are typically phenylene substituted with 1 to 4 alkyl groups (e.g., 1 to 3 alkyl groups or 1 to 2 alkyl groups) wherein each alkyl group has 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Examples include, but are not limited to, 2, 6-dimethyl-m-phenylenediamine and 2, 6-diethyl-m-phenylenediamine.

Suitable hydroxyl-containing compounds which can be complexed with Lewis acids are generally polyols. The polyol can have two or more hydroxyl groups (e.g., 2 to 6 hydroxyl groups or 2 to 4 hydroxyl groups). In some embodiments, the polyol is an alkylene glycol (i.e., alkylene glycol), a dialkylene glycol, or a polyalkylene glycol having more than 2 alkylene segments. Suitable alkylene glycols typically have 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Exemplary alkylene glycols include, but are not limited to, ethylene glycol, propylene glycol, 1, 2-propanediol, butanediol, 1, 3-butanediol, 2-methyl-1, 3-propanediol, 2-dimethyl-1, 3-propanediol, 1, 5-pentanediol, 2-ethyl-1, 3-pentanediol, 2-ethyl-1, 6-hexanediol, 1, 8-octanediol, 1, 4-cyclohexanediol, neopentyl glycol, bis (hydroxymethyl) cyclohexane, and 1, 18-octadecanediol. Suitable dialkylene glycols and polyalkylene glycols typically have alkylene segments containing 2 to 6 carbon atoms or 2 to 4 carbon atoms. Examples include, but are not limited to, ethylene glycol, diethylene glycol, glycerol, propylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol. The polyalkylene glycol typically has a weight average molecular weight of no greater than 10,000 daltons, no greater than 5,000 daltons, no greater than 1,000 daltons, or no greater than 500 daltons. The polyalkylene glycol typically has a weight average molecular weight of at least 100 daltons, at least 200 daltons, or at least 300 daltons. In other embodiments, the polyol is an aliphatic compound having more than two hydroxyl groups. Examples include, but are not limited to, glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, 2-ethyl-2- (hydroxymethyl) -1, 3-propanediol, 1,2, 6-hexanetriol, mannitol, and sorbitol. In other embodiments, the polyol is an aromatic compound, such as m-cresol or p-cresol.

Once the porogen is removed, the curing agent and/or curing catalyst may be positioned (i.e., loaded) in the porous polymeric core particle using any suitable method. The curing agent and/or curing catalyst is typically positioned within the polymeric core particle prior to forming the fluoropolymer-containing coating layer around the polymeric core particle. In some embodiments, the curing agent and/or curing catalyst is a liquid at room temperature, and the polymer core particle is mixed with the liquid to load the curing agent and/or curing catalyst (e.g., to position the curing agent and/or curing catalyst within the polymer core particle). In other embodiments, the curing agent and/or curing catalyst may be dissolved in a suitable organic solvent or water and expose the polymeric core particles to the resulting solution. Any organic solvent used is generally selected so that it does not dissolve the polymer core particles. When an organic solvent or water is used, at least some of the organic solvent or water may be loaded within the polymer core particles in addition to the curing agent and/or curing catalyst.

When the curing agent and/or curing catalyst is dissolved in an organic solvent or water, the concentration is typically selected to be as large as possible to shorten the time required to load the appropriate amount of curing agent and/or curing catalyst into the polymer core particles. The amount of curing agent and/or curing catalyst loaded and the amount of time required to load (i.e., position within the polymeric core particle) generally depends on, for example, the composition of the monomers used to form the polymeric core particle, the stiffness (e.g., amount of crosslinking) of the polymeric core particle, and the compatibility of the curing agent and/or curing catalyst with the polymeric core particle. The loading time is typically less than 24 hours, less than 18 hours, less than 12 hours, less than 8 hours, less than 4 hours, less than 2 hours, less than 1 hour, less than 30 minutes, less than 15 minutes, or less than 5 minutes. After loading, the particles are typically separated from the solution containing the curing agent and/or curing catalyst by decanting, filtering, centrifuging, drying, and the like.

The volume of curing agent and/or curing catalyst loaded may be up to the volume of poly (propylene glycol) removed from the polymerization product used to form the polymeric core particle. That is, the curing agent and/or curing catalyst may fill the voids left after the poly (propylene glycol) is removed. In many embodiments, the amount of curing agent and/or curing catalyst in the composite particle may be up to 70 weight percent, up to 60 weight percent, up to 50 weight percent, or up to 40 weight percent, based on the total weight of the composite particle. The amount may be at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or at least 50 wt%. For example, the curing agent and/or curing catalyst in the composite particle may be in the range of 1 wt% to 70 wt%, in the range of 1 wt% to 60 wt%, in the range of 5 wt% to 50 wt%, in the range of 5 wt% to 40 wt%, in the range of 5 wt% to 30 wt%, in the range of 5 wt% to 20 wt%, in the range of 10 wt% to 60 wt%, in the range of 10 wt% to 30 wt%, in the range of 20 wt% to 60 wt%, in the range of 20 wt% to 50 wt%, in the range of 30 wt% to 50 wt%, or in the range of 40 wt% to 50 wt%, based on the total weight of the composite particle.

The fluoropolymer-containing coating is positioned around the porous polymeric core particle loaded with the curative and/or cure catalyst (i.e., the fluoropolymer-containing coating is positioned around the loaded polymeric core particle). Any suitable fluorinated polymer may be used which is thermoplastic and allows the curing agent and/or curing catalyst to be released from the porous polymeric core particle through the coating. The fluorinated polymer included in the coating is typically a thermoplastic polymer that softens when exposed to heat. The thermoplastic is typically selected so as to be tack-free (i.e., the glass transition temperature of the fluorinated polymer is typically at least 20 ℃, at least 30 ℃, at least 40 ℃, or at least 50 ℃). The fluorinated polymer is typically a linear polymer and is not crosslinked or crosslinked to such a small amount that it can be dissolved in a suitable solvent, which is typically a fluorinated solvent.

The fluorinated polymer is typically the polymerization product of a monomer composition (second monomer composition) comprising one or more fluorinated monomers. The fluorinated monomer typically has a (meth) acryloyl group. In many embodiments, the fluorinated monomer is represented by formula (X):

Rf-Q-O-(CO)-CR¹＝CH₂

(X)

wherein R is¹Is hydrogen or methyl, Rf is a fluorinated alkyl group, and Q is a divalent linking group. The group Q is not fluorinated. The group Rf may be partially or fully fluorinated (i.e., the fluorinated alkyl group is a perfluoroalkyl group).

In some embodiments, the fluorinated alkyl group has zero or one hydrogen atom. That is, the fluorinated alkyl group is a perfluoroalkyl group (i.e., the fluorinated alkyl group does not have a hydrogen atom), or the fluorinated alkyl group has a single hydrogen atom at the end of the Rf group furthest from the group Q (i.e., the hydrogen atom is attached to the carbon atom furthest from the group Q). Suitable Rf fluorinated alkyl groups typically have at least 1 carbon atom, at least 2 carbon atoms, or at least 3 carbon atoms, and may have up to 12 carbon atoms, up to 10 carbon atoms, up to 8 carbon atoms, or up to 6 carbon atoms. In many embodiments, the Rf group has 3 to 5 carbon atoms.

Any suitable divalent Q linking group may be used. Exemplary Q groups include, but are not limited to, -SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-、-(CH₂)_k-O-(CH₂)_k-、-(CH₂)_k-SO₂-(CH₂)_k-、-(CH₂)_k-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-S-(CH₂)_k-、-(CO)-NR¹¹-(CH₂)_k-、-CH₂CH(OR¹²)-CH₂-、-(CH₂)_k-SO₂-and-O- (CO) -NR¹¹-(CH₂)_k-. In these Q groups, R¹¹Is hydrogen, alkyl or aryl. Radical R¹²Is hydrogen or alkyl. Is suitable for R¹¹And R¹²The alkyl group of (a) has 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. R¹¹The aryl group may have 6 to 10 carbon atoms, but is typically phenyl. The variable k is an integer in the range of 1 to 20, 1 to 10, 1 to 6, 1 to 4, or 1 to 3.

In some embodiments, the fluorinated monomer of formula (X) has formula (X-1), wherein the linking group Q in formula (X) is- (CH)₂)_k-。

Rf-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-1)

In the formula (X-1), the group R¹And Rf and the variable k are as defined above for formula (X). In some embodiments, Rf has 3 or 5 carbon atoms and the variable k is 1 or 2. Specific examples of fluorinated monomers of formula (X) include, but are not limited to C₃F₇CH₂O(CO)C(CH₃)＝CH₂、C₃F₇CH₂CH₂O(CO)C(CH₃)＝CH₂、C₅F₁₁CH₂O(CO)C(CH₃)＝CH₂And C₅F₁₁CH₂CH₂O(CO)C(CH₃)＝CH₂。

In other embodiments, the fluorinated monomer of formula (X) has formula (X-2), wherein the linking group Q in formula (X) is-SO₂-NR¹¹-(CH₂)_k-。

Rf-SO₂-NR¹¹-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

In the formula (X-2), the groups Rf and R¹¹、R¹And the variable k is as defined for formula (X) or the group Q in formula (X). In some embodiments, Rf has 1 to 6 carbon atoms or 3 to 6 carbon atoms, and k is equal to 2. Specific examples of fluorinated monomers of formula (XI) include, but are not limited to C₄F₉SO₂N(CH₃)CH₂CH₂O(CO)C(CH₃)＝CH₂、C₄F₉SO₂N(CH₃)CH₂CH₂O(CO)CH＝CH₂、C₄F₉SO₂N(C₄H₉)CH₂CH₂O(CO)C(CH₃)＝CH₂、C₄F₉SO₂N(C₈H₁₇)CH₂CH₂O(CO)C(CH₃)＝CH₂、

C₄F₉SO₂NHCH₂CH₂O(CO)C(CH₃)＝CH₂、C₆F₁₃SO₂N(CH₃)CH₂CH₂O(CO)C(CH₃)＝CH₂And CF₃SO₂N(CH₃)CH₂CH₂O(CO)C(CH₃)＝CH₂。

Fluorinated monomers of formula (X), such as those of formula (X-1) or (X-2), can be polymerized to form homopolymers or can be copolymerized with various non-fluorinated monomers such as alkyl (meth) acrylates of formula (XI).

R¹³-O-(CO)-CR¹＝CH₂

(XI)

In formula (XI), the radical R¹Is hydrogen or methyl, and the radical R¹³Is an alkyl group having at least 1 carbon atom, at least 2 carbon atoms, at least 4 carbon atoms, at least 6 carbon atoms, or at least 10 carbon atoms, and having up to 20 carbon atoms, up to 16 carbon atoms, or up to 12 carbon atoms. In some embodiments, R¹⁴Having 1 to 20 carbon atoms, such as 4 to 20 carbon atoms, 4 to 12 carbon atoms, 10 to 20 carbon atoms, or 16 to 20 carbon atoms. Depending on the number of carbon atoms, the alkyl group can be linear, branched, cyclic, or a combination thereof (e.g., it can have a linear or branched group as well as a cyclic group).

The copolymer formed from the second monomer composition comprising both the fluorinated monomer of formula (X) and the alkyl (meth) acrylate monomer of formula (XI) typically comprises at least 30 weight percent of the monomer of formula (X). For example, the second monomer composition comprises at least 35 wt.%, at least 40 wt.%, or at least 50 wt.%, and at most 99 wt.%, at most 95 wt.%, at most 90 wt.%, at most 80 wt.%, at most 70 wt.%, or at most 60 wt.% of the fluorinated monomer of formula (X). In some of these examples, the only other monomer in the second monomer composition is an alkyl (meth) acrylate of formula (XI). That is, the second monomer composition comprises, for example, 30 to 99% by weight of the fluorinated monomer of formula (X) and 1 to 70% by weight of the monomer of formula (XI), 30 to 90% by weight of the fluorinated monomer of formula (X) and 10 to 70% by weight of the alkyl (meth) acrylate of formula (XI), 30 to 80% by weight of the fluorinated monomer of formula (X) and 20 to 70% by weight of the alkyl (meth) acrylate of formula (XI), 50 to 99% by weight of the fluorinated monomer of formula (X) and 1 to 50% by weight of the alkyl (meth) acrylate of formula (XI). These weight percent amounts are based on the total weight of monomers in the second monomer composition.

The second monomer composition containing a fluorinated monomer of formula (X), such as those of formula (X-1) or (X-2), may optionally comprise a polar monomer, such as (meth) acrylic acid. Polar monomers can facilitate adhesion of the fluorinated coating to the porous polymeric core particle. If (meth) acrylic acid is included in the second monomer composition, its concentration is generally not greater than 5% by weight, based on the total weight of monomers in the second monomer composition. For example, the amount may be at least 0.5 wt%, at least 1 wt%, at least 1.5 wt%, or at least 2 wt%, and may be at most 5 wt%, at most 4 wt%, or at most 3 wt%. If used in greater amounts, the resulting fluorinated copolymer may not be sufficiently hydrophobic. That is, the second monomer composition comprises 0.5 to 5 wt% of a polar monomer (such as (meth) acrylic acid) and 95 to 99.5 wt% of a fluorinated monomer of formula (X).

In some embodiments, the second monomer composition can comprise 30 to 100 weight percent of the fluorinated monomer of formula (X), 0 to 70 weight percent of the alkyl (meth) acrylate of formula (XI), and 0 to 5 weight percent of (meth) acrylic acid. Such monomer compositions typically comprise 30 to 99 weight percent of the fluorinated monomer of formula (X), 1 to 70 weight percent of the alkyl (meth) acrylate of formula (XI), and 0.5 to 5 weight percent of (meth) acrylic acid. For example, the second monomer composition can comprise 30 to 70 weight percent of the fluorinated monomer of formula (X), 30 to 70 weight percent of the alkyl (meth) acrylate of formula (XI), and 0.5 to 5 weight percent of (meth) acrylic acid, or 50 to 95 weight percent of the fluorinated monomer of formula (X), 1 to 50 weight percent of the alkyl (meth) acrylate of formula (XI), and 0.5 to 5 weight percent of (meth) acrylic acid.

In some applications, the second monomer composition comprises a monomeric dye having a (meth) acryloyl group and a ring structure having multiple aromatic rings. The ring structure is typically fluorescent. Such monomers can help determine whether the fluorinated polymer surrounds the loaded porous polymeric core particle. Exemplary monomeric dyes include, but are not limited to, compounds of the following formulas (XII) through (XV), which are further more fully described in U.S. patent 6,894,105B2(Parent et al). The variables in these formulae are at least 1, at least 2, at least 3, at least 4, or at least 5, and can be at most 15, at most 10, or at most 8. The variable m is typically in the range of 1 to 15, 1 to 10, 1 to 8, 2 to 8, or 4 to 8.

If a dye monomer is included in the monomer composition, it is typically used in an amount equal to at least 0.001 weight percent, at least 0.005 weight percent, at least 0.01 weight percent, at least 0.05 weight percent, at least 0.1 weight percent, or at least 0.5 weight percent, and may be used in an amount up to 3 weight percent, up to 2 weight percent, or up to 1 weight percent. The amount is based on the total weight of monomers in the second monomer composition.

The fluorinated polymer is formed from the second monomer composition in the presence of an initiator for free radical polymerization. The same types of initiators and amounts of initiators discussed above for preparing the porous polymeric core particles can be used to form the fluorinated polymer.

The polymerization reaction to form the fluorinated polymeric material is typically carried out in the presence of an organic solvent. Examples of suitable solvents include, for example, aliphatic and alicyclic hydrocarbon solvents (e.g., hexane, heptane, and cyclohexane), aromatic solvents (e.g., benzene, toluene, and xylene), ethers (e.g., diethyl ether, dimethoxyethane, bis (2-methoxyethyl) ether, and diisopropyl ether), esters (e.g., ethyl acetate, and butyl acetate), alcohols (e.g., ethanol, and isopropanol), ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone), sulfoxides (e.g., dimethyl sulfoxide), amides (e.g., N-dimethylformamide, and N, N-dimethylacetamide), halogenated solvents (e.g., methyl chloroform, 1, 2-trichloro-1, 2, 2-trifluoroethane, trichloromethane, or trifluorotoluene), and mixtures thereof. In some embodiments, an ester solvent, such as ethyl acetate or butyl acetate, is used.

The molecular weight of the fluorinated polymer may be selected and/or controlled based on the concentration and activity of the initiator, the concentration of the monomer in the reaction mixture, and the amount and selection of the organic solvent. The weight average molecular weight is typically at least 5,000 daltons (Da), at least 10,000Da, or at least 15,000Da, and may be up to 100,000Da or higher, up to 80,000Da, up to 60,000Da, or up to 50,000 Da. If the molecular weight is too high, it may be difficult to dissolve the fluorinated polymer in an appropriate solvent system (e.g., fluorinated solvent) to provide a coating solution.

The fluorinated polymer is typically dissolved in a suitable solvent to provide a coating solution that is mixed with the loaded porous polymeric core particles. The composition of the coating solution is typically selected so that a significant amount of the curing agent and/or curing catalyst is not extracted from the loaded polymeric core particles during deposition of the coating layer. The curing agent and/or curing catalyst is generally relatively polar compared to the coating solution. Thus, the curing agent and/or curing catalyst is typically not or minimally extracted from the porous polymeric core particle during the process of depositing the coating. In some embodiments, the coating solution extracts less than 10 wt%, less than 5 wt%, less than 3 wt%, less than 2 wt%, less than 1 wt%, or less than 0.5 wt% of the curing agent and/or curing catalyst from the loaded polymeric core particles.

In some embodiments, the coating solution used to form the coating layer comprises a fluorinated polymer dissolved in a fluorinated solvent. The fluorinated solvent is typically a hydrofluoroether of formula (XVI).

(R¹⁴-O)_z-Rf¹

(XVI)

In formula (XVI), the radical R¹⁴Is alkyl, the variable z is 1 to 2, and Rf¹Is a perfluoroalkyl group (when z equals 1) or a perfluoroalkylene group (when z equals 2). Perfluoroalkyl or perfluoroalkylene Rf¹Radical and alkyl radical R¹⁴Each of the groups typically has 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms.

Some exemplary fluorinated solvents are n-C₄F₉OCH₃、n-C₄F₉OCH₂CH₃、CF₃CF(CF₃)CF₂OCH₃、CF₃CF(CF₃)CF₂OCH₂CH₃、C₈F₁₇OCH3、CH₃O-(CF₂)₄-OCH₃And C₅F₁₁OC₂H₅、(CF₃)₂CFOCH₃、CF₃-CF(CF₃)-CF(OC₂H₅)-CF₂CF₂CF₃、CF₃-c[N(CF₂CF₂)₂O]And (CF)₃)₂CF-c[N(CF₂CF₂)₂O]Wherein-c [ N (CF)₂CF₂)₂O]Is a cyclic group. Fluorinated solvents are commercially available under the trade name NOVEC from 3M Company (Saint Paul, MN, USA) of Saint Paul, minnesota. These include NOVEC 7100 (which is C)₄F₉-OCH₃) NOVEC 7200 (which is C)₄F₉OCH₂CH₃) And NOVEC 7500 (which is CF)₃-CF(CF₃)-CF(OC₂H₅)-CF₂CF₂CF₃)。

Typically, the only solvent contained in the coating solution is a fluorinated solvent. However, other non-fluorinated solvents that are miscible with the fluorinated solvent may be included. For example, the coating solution may comprise ethyl acetate and propylene glycol methyl ether acetate, which is commercially available from Dow Chemical company (milrand, MI, USA) under the trade name DOWANOL PMA. Typically, the non-fluorinated solvent is included in an amount in the range of 0 wt% to 10 wt%, 0 wt% to 8 wt%, 1 wt% to 10 wt%, 1 wt% to 8 wt%, 2 wt% to 10 wt%, or 2 wt% to 8 wt%, based on the total weight of the fluorinated solvent and the non-fluorinated solvent. In many embodiments, the solvent in the coating solution is a 100% fluorinated solvent.

The amount of fluorinated polymer in the coating solution depends on its solubility in the fluorinated solvent, the desired viscosity of the coating solution and the desired thickness of the coating. The coating solution typically comprises at least 5 wt.%, at least 10 wt.%, at least 15 wt.%, or at least 20 wt.% solids. The weight percent solids corresponds to the weight percent of fluorinated polymer in the coating solution. The weight percent solids may be up to 70 weight percent or even greater, up to 60 weight percent, up to 50 weight percent, up to 40 weight percent, or up to 30 weight percent. For example, the weight percent solids can be in a range of 10 to 70 weight percent, in a range of 20 to 60 weight percent, in a range of 20 to 50 weight percent, or in a range of 20 to 40 weight percent.

In many embodiments, the maximum percent solids generally corresponds to a coating solution having the highest viscosity that can be pumped. A high solids content may be desirable because less solvent needs to be removed during the process of forming the coating. However, if the percent solids is too high, the coating will be more likely to surround the plurality of loaded polymeric core particles. In many embodiments, a dilute coating solution is used to increase the likelihood of forming composite particles comprising a single charge of polymeric core particles.

Any suitable method may be used to deposit the coating around the polymeric core particles. In most embodiments, the polymeric core particle comprises a supported curing agent and/or a supported curing catalyst when the coating is deposited. That is, the coating is formed around the loaded polymer core particle. The coating solution is mixed with the loaded polymer core particles. After thorough mixing, the solvent is removed to provide a coating around the loaded polymer core particles.

In some embodiments, the coating layer surrounding the polymeric core particles is formed by spray drying (spray and dry) or similar processes, such as fluid bed coating and drying are generally considered to be better, which can result in a coating layer having a relatively uniform thickness being formed around the loaded polymeric core particles. These processes can be used to provide composite particles having a single, rather than multiple, loading of the polymer core particles, if conditions are appropriately selected. That is, the composite particle has a core-shell arrangement in which the coating surrounds a single loaded polymeric core particle.

Using spray drying, the loaded polymer core particles are mixed with a coating solution to form a slurry. The slurry is then pumped to a drying chamber that includes a nebulizer (to form droplets) and a drying gas. Some common types of atomization include rotating wheel (centrifugal) atomization, single fluid/pressure nozzle (hydraulic) atomization, two fluid nozzle (pneumatic) atomization, and ultrasonic atomization. The product, which is a dried composite particle, can be collected by various methods, such as by gravity or by using cyclones, filters and filter bags, electrostatic separation, and the like.

Although any suitable atomization process may be used, a two-fluid nozzle atomizer is typically used. Using these sprayers, a first fluid (e.g., a slurry) is pumped through a small orifice, and a second fluid, typically air or nitrogen, is supplied proximate to the small orifice to further atomize the first fluid. Increasing the ratio of the second fluid to the first fluid generally decreases the slurry droplet size and increases the likelihood of having a single loading of particles within the coating.

Dual fluid systems may have internal mixing (introducing the second fluid into the first fluid before exiting the last orifice) or external mixing (introducing the second fluid after the first fluid exits the last orifice). A variety of different configurations may be used for introducing the second fluid relative to the first fluid. For example, the configuration may be a circular spray (concentric ring of second fluid around the first fluid orifice), a conical/hollow spray, an angular/flat spray, a swirl spray, or the like. Nebulizers having these different configurations are available from a variety of suppliers, such as nebulizing Systems Co (Wheaton, illinois, USA).

For flows of large amounts of drying gas into and out of the drying chamber, a number of options can be used. To maintain sufficient thermal energy and provide a drying gas with sufficient drying capacity (e.g., low dew point), the drying gas is typically continuously circulated through the drying chamber. The main categories of flow patterns of the drying gas with respect to the atomized droplets (input material) are co-current flow, counter-current flow and mixed flow. Co-current flow involves the input material traveling in the same direction as the bulk of the drying gas; this is typically embodied as the input material traveling downwardly with a mass of drying gas traveling downwardly immediately after atomization (e.g., downward spraying). Since the hot drying gas is cooled by the drying droplets, co-current flow is generally advantageous for temperature sensitive systems, so the solid material never experiences the temperature of the incoming hot drying gas. Counter-current flow involves the input material traveling in the opposite direction to the bulk of the drying gas; this is typically embodied as the input material traveling downward immediately after atomization (e.g., downward spraying) while the bulk of the drying gas travels upward. This flow is generally used for most effective drying. Mixed flow is a combination of co-current flow and counter-current flow, where in some zones the input material travels in the same direction as the bulk of the drying gas, but in other zones it travels in the opposite direction. This flow pattern is most commonly seen when atomizing an input material in an upward direction, where the input material initially travels upward with energy applied thereto by atomization, but is subsequently pulled downward by gravity. Because the input material travels in both directions, the bulk of the drying gas will travel with the input material in some places and against the input material in other places, whether the bulk of the drying gas travels downward or upward. The mixed flow may be advantageous because it provides a longer residence time for the dry solids in the drying chamber.

The drying temperature is typically selected based on the composition of the loaded polymer core particles and the coating solution. In many embodiments, the bulk of the drying gas at the outlet of the drying chamber has a temperature near the boiling point of the solvent used in the slurry (in the coating solution) to ensure that sufficient drying occurs. However, this does result in the dried solid reaching a temperature close to the boiling point of the solvent. In most cases, this can be advantageous because it minimizes residual liquid, which can lead to improved flow capacity, reduced hazard from the presence of volatile organic solvents, and reduced unnecessary quality.

However, for some composite particles, the use of such high drying temperatures may be undesirable. Such a case may be, for example, one in which any component of the composite particle has a glass transition temperature, a melting temperature, or a decomposition temperature close to the boiling point of the solvent contained in the slurry. In particular, care must be taken to prevent or minimize the release of the curing agent and/or curing catalyst from the composite particles. In such cases, the drying temperature is typically lowered below a temperature at which any undesirable changes to the composite particles may occur. Drying can be accomplished at lower temperatures, for example, by increasing residence time in the drying chamber, increasing the flow rate of the drying gas, reducing the evaporation load, or modifying various flow patterns.

Multiple coatings may be positioned around the loaded polymer core particle. Typically, multiple layers are added to provide a thicker coating or to modify the release characteristics of the curing agent and/or curing catalyst from the porous composite particle. If multiple coatings are used, they are typically selected to be compatible with each other. In many embodiments, the same fluorinated polymer is used to form multiple coatings.

The coating may have any desired thickness. In some embodiments, the thickness is at least 0.1 microns, at least 0.2 microns, at least 0.5 microns, at least 0.75 microns, or at least 1.0 micron. The thickness may be up to 5 microns or more, up to 4 microns, up to 3 microns, or up to 2 microns. The release profile of the curing agent and/or curing catalyst within the composite particles can generally be controlled by the thickness of the coating. That is, the greater the thickness, the slower the release rate of the curing agent and/or curing catalyst through the coating. On the other hand, the release rate of the curing agent and/or curing catalyst can be increased by reducing the thickness of the coating. The thickness is typically in the range of 0.1 to 5 microns, in the range of 0.1 to 3 microns, in the range of 0.5 to 5 microns, in the range of 0.5 to 3 microns, in the range of 1 to 5 microns, in the range of 1 to 3 microns, in the range of 0.1 to 2 microns, in the range of 0.5 to 2 microns, or in the range of 1 to 2 microns.

The desired thickness of the coating can be used to calculate the theoretical weight of the fluorinated polymer that should be deposited on the loaded polymer core particle to provide that thickness. More specifically, the mass of the shell may be calculated using equation (1).

m_Shell＝m_p(ρ_Shell/ρ_p)[(D_tot)³/(D_p)³–1] (1)

Wherein m is_ShellIs the mass of the shell (i.e., coating) in grams, m_pIs the mass of the loaded polymer core particles in grams, p_ShellIs the density of the shell in grams per cubic centimeter, p_pIs the density of the loaded polymer core particles in grams per cubic centimeter, D_totIs the diameter of the composite particle in centimeters, and D_pIs a polymerizationThe diameter of the core particle (e.g., loaded polymer core particle) is in centimeters. Diameter D_pThe determination may be made using any of a variety of methods, such as measuring the diameter of particles in an electron micrograph. Diameter D_totIs equal to D_pPlus the desired shell thickness. The density of the loaded polymer core particles is typically about 0.5cm³In terms of/g, but can be measured using procedures known to those skilled in the art. The density of the shell is the density of the fluorinated polymer contained in the coating solution. Alternatively, equation (1) can be used to calculate the theoretical thickness of the coating (i.e., shell) based on the total mass of fluorinated polymer contained in the coating solution.

As an alternative to spray drying or similar processes, the mixture of loaded polymer core particles and coating solution may be spread into a thin layer for drying purposes. Any suitable drying method may be used. The dried layer may then be fractured to provide composite particles. For example, the dried layer may be placed in a blender or dry mill to separate the particles from each other. The percent solids in the thin layer is typically relatively low to reduce the likelihood of having multiple loaded polymer core particles within the same porous composite particle. This approach may be used when a relatively uniform coating thickness is not necessary or where multiple coating thicknesses may be desired to provide a broader release rate profile for the curing agent and/or curing catalyst. In addition, this approach can be used when it may be beneficial to have multiple loaded polymer core particles surrounded by the same coating to provide a distribution of release rates.

The composite particles typically comprise at least 20 wt% of the porous polymeric core particle, at least 0.1 wt% of a curing agent and/or curing catalyst, and at least 10 wt% of a coating layer, based on the total weight of the porous composite particle. In some examples, the composite particle may comprise at least 30 wt% of the porous polymeric core particle, at least 0.5 wt% of the curing agent and/or curing catalyst, and at least 20 wt% of the coating layer. In other examples, the composite particle may comprise at least 40 wt% of the porous polymeric core particle, at least 1 wt% of the curing agent and/or curing catalyst, and at least 30 wt% of the coating layer.

The composite particles typically comprise up to 90 wt% of the porous polymeric core particles, up to 70 wt% of a curing agent and/or curing catalyst and up to 80 wt% of a coating layer. In some examples, the composite particle may comprise up to 80 wt% of the porous polymeric core particle, up to 50 wt% of the curing agent and/or curing catalyst, and up to 70 wt% of the coating layer. In other examples, the composite particle may comprise up to 70 wt% of the porous polymeric core particle, up to 40 wt% of the curing agent and/or curing catalyst, and up to 60 wt% of the coating layer.

In some embodiments, the composite particle comprises 20 to 90 wt% of the porous polymeric core particle, 1 to 70 wt% of the curing agent and/or curing catalyst, and 10 to 80 wt% of the coating layer. In some examples, the composite particle comprises 30 to 80 wt% of the porous polymeric core particle, 1 to 50 wt% of the curing agent and/or curing catalyst, and 20 to 70 wt% of the coating layer. In other examples, the composite particle comprises 30 to 75 wt% of the porous polymeric core particle, 5 to 50 wt% of the curing agent and/or curing catalyst, and 25 to 70 wt% of the coating layer. In other examples, the composite particle comprises 30 to 70 weight percent of the porous polymeric core particle, 5 to 40 weight percent of the curing agent and/or curing catalyst, and 30 to 70 weight percent of the coating layer.

For many embodiments of the resulting composite particles, the coating surrounds the loaded porous polymeric core particle as a shell layer. In other words, the composite particle is a core-shell polymer core particle. The coating encapsulates the curing agent and/or curing catalyst within the porous polymeric core particle (i.e., the coating encapsulates the loaded polymeric core particle). The porous composite particles have a core-shell structure prior to release of the curing agent and/or curing catalyst, wherein the porous polymeric core particles comprise a loading of the curing agent and/or curing catalyst. In some embodiments, a shell layer (coating) surrounds a single porous polymeric core particle. That is, the composite particle comprises a single loaded polymeric core particle. However, in other embodiments, the shell surrounds a plurality of loaded polymeric core particles. That is, the composite particle comprises a plurality of loaded polymeric core particles within a common shell (coating).

In many embodiments, the loaded polymeric core particles are not tacky. This increases the likelihood that the plurality of loaded polymeric core particles will not stick together prior to or during application of the coating. The lack of tackiness of the loaded polymeric core particles increases the likelihood that the coating will be positioned around a single polymeric core particle rather than around multiple loaded polymeric core particles.

In another aspect, a curable composition is provided. The curable composition includes (1) an epoxy resin and (2) composite particles mixed with the epoxy resin. As described above, the composite particle comprises (a) a porous polymeric core particle, (b) a curing agent and/or curing catalyst for an epoxy resin positioned within, but not covalently bound to, the porous polymeric core particle, and (c) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

The composite particles are mixed with an epoxy resin. While any suitable amount of composite particles may be combined with the epoxy resin, the amount generally depends on the amount and type of curing agent and/or curing catalyst loaded into the composite particles. For example, a greater amount of curing agent is used (particularly if the curing agent is of the formula-NR having at least two) than the curing catalyst⁷Compounds of the group of H). Having at least two formulae-NR⁷The compounds of the group of H tend to react directly with the epoxy resin, while the curing catalyst, as its name implies, acts as a catalyst for the ring-opening reaction of the oxirane group.

In many embodiments, the amount of composite particles included in the curable composition is at least 0.1 weight percent based on the combined weight of the composite particles and the epoxy resin. If lower amounts are used, there may be an insufficient amount of curing agent and/or curing catalyst to polymerize the epoxy resin. The amount of composite particles may be, for example, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, or at least 5 wt%. The amount of composite particles may be up to 35 wt%. If the amount of composite particles is high, the final cured composition may be too soft (which may have less than the desired amount of strength integrity). The amount of composite particles may be, for example, up to 30 wt%, up to 25 wt%, up to 20 wt%, up to 15 wt%, or up to 10 wt%. In some exemplary embodiments, the amount is in the range of 0.1 wt% to 35 wt%, in the range of 0.5 wt% to 30 wt%, in the range of 0.5 wt% to 25 wt%, in the range of 0.5 wt% to 20 wt%, in the range of 0.5 wt% to 10 wt%, in the range of 1 wt% to 30 wt%, in the range of 1 wt% to 20 wt%, or in the range of 1 wt% to 10 wt%. The weight percent values are based on the total weight of the cured composition.

The composite particles are typically heated in the presence of an epoxy resin to release the curing agent and/or curing catalyst. To be released from the polymeric core particles within the composite particles, the curing agent and/or curing catalyst typically diffuses through a coating positioned around the loaded polymeric core particles. Diffusion may occur, for example, through openings or voids within the polymer matrix of the coating, through defects in the coating, or by any other mechanism. The thickness and composition of the coating and the environment surrounding the composite particle can affect the rate at which the curing agent and/or curing catalyst diffuses out of the loaded polymer core particle and through the coating.

Depending on the circumstances and other factors, release may or may not occur immediately upon heating. That is, the initiation of the release of the curing agent and/or curing catalyst may begin immediately or after a period of time. However, once release is initiated, the amount of curing agent and/or curing catalyst released is typically initially maximized and then decreases over time. Such a release profile may rise as the concentration of curing agent and/or curing catalyst is greater at the outer edges of the loaded polymer core particles. Such a release profile may also be increased when the curing agent and/or curing catalyst is uniformly distributed throughout the loaded polymer core particle, as additional time is required for diffusion from the interior region of the loaded polymer core particle.

The epoxy resin contained in the curable epoxy resin composition contains at least one epoxy functional group (i.e., oxirane group) per molecule. As used herein, the term ethylene oxide group refers to the following divalent group.

The asterisk represents the site where the ethylene oxide group is attached to another group. The oxirane groups are typically bonded to hydrogen atoms if they are in a terminal position of the epoxy resin.

The terminal oxirane group is typically part of a glycidyl group.

Epoxy resins have at least one ethylene oxide group per molecule, and typically have at least two ethylene oxide groups per molecule. For example, the epoxy resin may have 1 to 10, 2 to 10, 1 to 6,2 to 6, 1 to 4, or 2 to 4 ethylene oxide groups per molecule. The oxirane group is typically part of a glycidyl group.

The epoxy resin may be a single material or a mixture of materials selected to provide the desired viscosity characteristics prior to curing and to provide the desired mechanical properties after curing. If the epoxy resin is a mixture of materials, at least one epoxy resin in the mixture is typically selected to have at least two ethylene oxide groups per molecule. For example, the first epoxy resin in the mixture may have two to four or more ethylene oxide groups, and the second epoxy resin in the mixture may have one to four ethylene oxide groups. In some of these examples, the first epoxy resin is a first glycidyl ether having two to four glycidyl groups and the second epoxy resin is a second glycidyl ether having one to four glycidyl groups.

The portion of the epoxy resin molecule that is not an oxirane group (i.e., the epoxy resin molecule minus the oxirane group) can be aromatic, aliphatic, or a combination thereof, and can be linear, branched, cyclic, or a combination thereof. The aromatic and aliphatic portions of the epoxy resin may contain heteroatoms or other groups that do not react with the oxirane groups. That is, the epoxy resin may comprise a halogenated group, an oxo group such as an oxo group in an ether linkage group, a thio group such as a thio group in a thioether linkage group, a carbonyl group, a carbonyloxy group, a carbonylimine group, a phosphono group, a sulfonyl group, a nitro group, a nitrile group, and the like. The epoxy resin may also be a silicone-based material, such as a polydiorganosiloxane-based material.

While the epoxy resin can have any suitable molecular weight, the weight average molecular weight is typically at least 100 daltons, at least 150 daltons, at least 175 daltons, at least 200 daltons, at least 250 daltons, or at least 300 daltons. For polymeric epoxy resins, the weight average molecular weight may be up to 50,000 daltons or even higher. The weight average molecular weight is typically at most 40,000 daltons, at most 20,000 daltons, at most 10,000 daltons, at most 5,000 daltons, at most 3,000 daltons, or at most 1,000 daltons. For example, the weight average molecular weight can be in the range of 100 daltons to 50,000 daltons, in the range of 100 daltons to 20,000 daltons, in the range of 100 daltons to 10,000 daltons, in the range of 100 daltons to 5,000 daltons, in the range of 200 daltons to 5,000 daltons, in the range of 100 daltons to 2,000 daltons, in the range of 200 daltons to 2,000 daltons, in the range of 100 daltons to 1,000 daltons or in the range of 200 daltons to 1,000 daltons.

Suitable epoxy resins are typically liquid at room temperature (e.g., about 20 ℃ to about 25 ℃ or about 20 ℃ to about 30 ℃). However, epoxy resins that are soluble in suitable organic solvents may also be used. In most embodiments, the epoxy resin is a glycidyl ether. Exemplary glycidyl ethers can have formula (XVII).

In formula (XVII), the radical R¹⁵Is a p-valent group that is aromatic, aliphatic, or a combination thereof. Radical R¹⁵And may be linear, branched, cyclic, or combinations thereof. Radical R¹⁵And optionally include halo groups, oxo groups, thio groups, carbonyl groups, carbonyloxy groups, carbonylimino groups, phosphono groups, sulfonyl groups, nitro groups, nitrile groups, and the like. While the variable p can be any suitable integer greater than or equal to 1, p is typically an integer in the range of 2 to 10, in the range of 2 to 6, or in the range of 2 to 4.

In some exemplary epoxy resins of formula (XVII), the variable p is equal to 2 (i.e., the epoxy resin is a diglycidyl ether), and R¹⁵Including alkylene (i.e., alkylene is a divalent group of an alkane and may be referred to as alkane-diyl), heteroalkylene (i.e., heteroalkylene is a divalent group of a heteroalkane and may be referred to as heteroalkane-diyl), arylene (i.e., a divalent group of an aromatic compound), or combinations thereof. Suitable alkylene groups typically have 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Suitable heteroalkylene groups typically have 2 to 50 carbon atoms, 2 to 40 carbon atoms, 2 to 30 carbon atoms, 2 to 20 carbon atoms, 2 to 10 carbon atoms, or 2 to 6 carbon atoms with 1 to 10 heteroatoms, 1 to 6 heteroatoms, or 1 to 4 heteroatoms. The heteroatom in the heteroalkylene can be selected from an oxo group, a thioxo group, or an-NH-group, but is typically an oxo group. Suitable arylene groups typically have 6 to 18 carbon atoms or 6 to 12 carbon atoms. For example, the arylene group can be phenylene or biphenylene. Radical R¹⁵And may optionally further comprise halo groups, oxo groups, thio groups, carbonyl groups, carbonyloxy groups, carbonylimino groups, phosphono groups, sulfonyl groups, nitro groups, nitrile groups, and the like. Variable p is led toOften an integer in the range of 2 to 4.

Some of the epoxy resins of formula (XVII) are diglycidyl ethers, wherein R is¹⁵Including (a) an arylene group or (b) an arylene group in combination with an alkylene, heteroalkylene, or both. Radical R¹⁵Optional groups such as halo groups, oxo groups, thio groups, carbonyl groups, carbonyloxy groups, carbonylimino groups, phosphono groups, sulfonyl groups, nitro groups, nitrile groups, and the like may also be included. These epoxy resins can be prepared, for example, by reacting an aromatic compound having at least two hydroxyl groups with an excess of epichlorohydrin. Examples of useful aromatic compounds having at least two hydroxyl groups include, but are not limited to, resorcinol, catechol, hydroquinone, p ' -dihydroxydibenzyl, p ' -dihydroxyphenyl sulfone, p ' -dihydroxybenzophenone, 2' -dihydroxyphenyl sulfone, and p, p ' -dihydroxybenzophenone. Other examples include the 2,2', 2,3', 2,4', 3', 3,4 'and 4,4' isomers of dihydroxydiphenylmethane, dihydroxydiphenyldimethylmethane, dihydroxydiphenylethylmethylmethane, dihydroxydiphenylmethylpropylmethane, dihydroxydiphenylethylphenylmethane, dihydroxydiphenylpropylphenylmethane, dihydroxydiphenylbutylphenylmethane, dihydroxydiphenyltolylethane, dihydroxydiphenyltolylmethylmethane, dihydroxydiphenyldicyclohexylmethane and dihydroxydiphenylcyclohexane.

Some commercially available diglycidyl ether epoxy resins of formula (XVII) are derived from bisphenol a (i.e., bisphenol a is 4,4' -dihydroxydiphenylmethane). Examples include, but are not limited to, those commercially available under the trade names EPON (e.g., EPON 828, EPON 872, EPON 1001, EPON 1004, EPON 2004, EPON 1510, and EPON 1310) from the vash corporation of columbu, redeon, OH, USA, under the trade names DER (e.g., DER 331, DER 332, DER 336, and DER 439) from Dow Chemical co. Other commercially available diglycidyl ether epoxy resins are derived from bisphenol F (i.e., bisphenol F is 2,2' -dihydroxydiphenylmethane). Examples include, but are not limited to, those commercially available under the trade name DER (e.g., DER 334) from Dow Chemical Co., Inc., those commercially available under the trade name EPICLON (e.g., EPICLON 830) from Dainippon Ink Chemical industries, Inc., Parsippany, NJ, USA, of Pacific Bonney, N.J., and those commercially available under the trade name ARALDITE (e.g., ARALDITE GY 281) from Huntsman Corporation, Woodlands, TX, USA, of Woodsan, U.S.A..

Other epoxy resins of formula (XVII) are diglycidyl ethers of poly (alkylene oxide) glycols. These epoxy resins may also be referred to as diglycidyl ethers of poly (alkylene glycol) glycols. The variable p is equal to 2, and R¹⁵Is a heteroalkylene having an oxygen heteroatom. The poly (alkylene glycol) moiety can be a copolymer or homopolymer, and typically comprises alkylene units having 1 to 4 carbon atoms. Examples include, but are not limited to, diglycidyl ethers of poly (ethylene oxide) glycols, diglycidyl ethers of poly (propylene oxide) glycols, and diglycidyl ethers of poly (tetrahydrofuran) glycols. Epoxy resins of this type are commercially available from Polysciences, Inc., Warrington, Pa., USA, Bayer's, such as those derived from poly (ethylene oxide) glycol or those derived from poly (propylene oxide) glycol having a weight average molecular weight of about 400 daltons, about 600 daltons, or about 1000 daltons.

Other epoxy resins of the formula (XVII) are the diglycidyl ethers (R) of alkane diols¹⁵Is alkylene and the variable p is equal to 2). Examples include diglycidyl ether of 1, 4-dimethanol cyclohexyl, diglycidyl ether of 1, 4-butanediol, and diglycidyl ether of cycloaliphatic diol formed from hydrogenated bisphenol-A, such as those commercially available under the trade name EPONEX (e.g., EPONEX 1510) from Vast corporation (Columbus, OH, USA, Ohio, Hexion, Inc., (Columbus, OH, USA), and from CVC thermoset specialty materials (CVC Thermose, N.J., EpALLOY 5001, Inc.) (CVC Thermose, Ohio, USA)t Specialties (Moorestown, NJ, USA)) are commercially available.

For some applications, the epoxy resin selected for use in the curable coating composition is a novolac epoxy resin (novolac), which is a glycidyl ether of a phenolic novolac resin (phenolic novolac). These resins can be prepared, for example, by reacting a phenol with an excess of formaldehyde in the presence of an acidic catalyst to produce a novolac resin. Novolac epoxy resins are then prepared by reacting novolac resins with epichlorohydrin in the presence of sodium hydroxide. The resulting novolac epoxy resins typically have more than two ethylene oxide groups and can be used to produce cured coating compositions having high crosslink density. The use of novolac epoxy resins may be particularly desirable in applications where corrosion resistance, water resistance, chemical resistance, or a combination thereof is desired. One such novolac epoxy resin is poly [ (phenyl glycidyl ether) -co-formaldehyde ]. Other suitable phenolic resins are commercially available under the trade names ARALDITE (e.g., ARALDITE GY289, ARALDITE EPN 1183, ARALDITE EP 1179, ARALDITE EPN 1139, and ARALDITE EPN 1138) from Huntsman Corporation (Woodlands, TX, USA), woodland, texas, USA, EPALLOY (e.g., EPALLOY 8230) from CVC thermosetting specialty materials, CVC thermoseitas, Moorestown, NJ, USA, and DEN (e.g., DEN 424 and DEN 431) from Dow Chemical company, Dow Chemical, Midland, MI, USA, michigan, USA.

Other epoxy resins include silicone resins having at least two glycidyl groups and flame retardant epoxy resins having at least two glycidyl groups (e.g., brominated bisphenol-type epoxy resins having at least two glycidyl groups, such as the brominated bisphenol-type epoxy resins commercially available under the tradename DER 580 from Dow Chemical co.

The epoxy resin is typically a mixture of materials. For example, the epoxy resin may be selected to provide a mixture of desired viscosity or flow characteristics prior to curing. The mixture may include at least one first epoxy resin referred to as a reactive diluent having a lower viscosity and at least one second epoxy resin having a higher viscosity. Reactive diluents tend to reduce the viscosity of the epoxy resin composition and typically have a saturated branched backbone or a saturated or unsaturated cyclic backbone. Examples include, but are not limited to, diglycidyl ether of resorcinol, diglycidyl ether of cyclohexanedimethanol, diglycidyl ether of neopentyl glycol, and triglycidyl ether of trimethylolpropane. Diglycidyl ether of cyclohexanedimethanol is commercially available under the trade name HELOXY modifer (e.g., HELOXY modifer 107) from the vast majority of columbia, ohio, USA (Hexion inc., in Columbus, OH, USA) and is commercially available under the trade name EPODIL (e.g., EPODIL 757) from Air Products and Chemicals, inc., allenton, PA, USA. Other reactive diluents have only one functional group (i.e., an oxirane group), such as various monoglycidyl ethers. Some exemplary monoglycidyl ethers include, but are not limited to, alkyl glycidyl ethers in which the alkyl group has an alkyl group of 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Some of the commercially available monoglycidyl ethers include those available under the trade name EPODIL from Air Products and Chemicals, Inc., Allentown, PA, USA, of Allentown, Pa., such as EPDIL 746 (2-ethylhexyl glycidyl ether), EPDIL 747 (aliphatic glycidyl ether), and EPDIL 748 (aliphatic glycidyl ether).

Other epoxy resins are designed to reduce amine blushing. These epoxy resins are typically added to the curable coating compositions at relatively low levels. Such epoxy resins are commercially available under The tradename DW 1765 from Huntsman Corporation, The Woodlands, TX, USA, in Wood, Tex. This material has a paste-like consistency but is based on liquid epoxy resins.

The curable coating composition typically comprises at least 20 wt% of an epoxy resin, based on the total weight of the curable coating composition. If lower levels are used, the cured coating composition may not contain enough polymeric material (e.g., epoxy resin) to provide the desired coating characteristics. Some curable coating compositions may comprise at least 25 wt.%, at least 30 wt.%, at least 40 wt.%, or at least 50 wt.% epoxy resin. The curable coating composition typically comprises up to 90 wt%, up to 85 wt%, up to 80 wt% of the epoxy resin, although higher amounts may be used if no filler is added. For example, the curable coating composition may comprise up to 75 wt%, up to 70 wt%, up to 65 wt%, or up to 60 wt% of the epoxy resin. Some examples of the curable coating composition include 20 to 90 wt%, 20 to 80 wt%, 20 to 70 wt%, 30 to 90 wt%, 30 to 80 wt%, 30 to 70 wt%, 30 to 60 wt%, 40 to 90 wt%, 40 to 80 wt%, 40 to 70 wt%, 40 to 60 wt%, 50 to 90 wt%, 50 to 80 wt%, or 50 to 70 wt% of the epoxy resin.

In addition to the epoxy resin and the composite particles, the curable composition may comprise various optional components. One such optional component is a toughening agent. Toughening agents may be added to provide the desired lap shear, peel resistance, and impact strength. Useful toughening agents are polymeric materials that can react with epoxy resins and can be crosslinked. Suitable toughening agents include polymeric compounds having two phases, a rubber phase and a thermoplastic phase, or compounds that are capable of forming both a rubber phase and a thermoplastic phase with an epoxy resin when cured. The polymers useful as toughening agents are preferably selected to inhibit cracking of the cured composition.

Some polymeric tougheners having both a rubber phase and a thermoplastic phase are acrylic core-shell polymers, wherein the core is an acrylic copolymer having a glass transition temperature of less than about 0 ℃. Such core polymers may include polybutylacrylate, isooctylacrylate, polybutadiene-polystyrene, the shell of which is composed of acrylic polymers having a glass transition temperature above about 25 ℃, such as polymethylmethacrylate. Commercially available core-shell polymers include those commercially available as dry powders from the Dow Chemical company (Dow Chemical Co.) under the trade names ACRYLOID KM 323, ACRYLOID KM 330, and PARALOID BTA 731, and those commercially available from the hounds Corporation (Osaka, Japan) under the trade name KANE ACE B-564. These core-shell polymers are also available as pre-dispersed blends with diglycidyl ethers of bisphenol-a, for example in a ratio of 12 to 37 parts by weight based on the weight of the core-shell polymer and are available under the trade names KANE ACE (e.g., KANE ACE MX 157, KANE ACE MX 257, and KANE ACE MX 125) from the bell-and-spigot company (Japan) (Kaneka Corporation (Japan)).

Another class of polymeric tougheners are carboxy-terminated butadiene acrylonitrile compounds such as those commercially available under the trade name HYCAR (e.g., HYCAR 1300X8, HYCAR 1300X13, and HYCAR 1300X17) from Lubrizol Advanced Materials, inc. (Cleveland, Ohio, USA) and PARALOID (e.g., PARALOID EXL-2650) from Dow Chemical company, Midland, michigan (Midland, MI, USA).

Other polymeric tougheners are graft polymers having two phases, a rubber phase and a thermoplastic phase, such as those disclosed in U.S. Pat. No. 3,496,250 (Czerwinski). These graft polymers have a rubber backbone onto which thermoplastic polymer segments are grafted. Examples of such graft polymers include, for example, methacrylate-butadiene-styrene and acrylonitrile/butadiene-styrene polymers. The rubber backbone is preferably prepared to constitute from about 95 wt.% to about 40 wt.% of the total graft polymer, such that the polymerized thermoplastic portion constitutes from about 5 wt.% to about 60 wt.% of the graft polymer.

Other polymeric tougheners are polyethersulfones such as those commercially available from BASF (Florham Park, NJ, USA) under the trade name ULTRASON (e.g., ULTRASON E2020P SR MICRO).

The curable composition may additionally comprise a non-reactive plasticizer to modify the rheological properties. Commercially available plasticizers include those available under the trade designation BENZOFLEX 131 from Eastman Chemical company (kingsburg, tennessee, USA), JAYFLEX DINA from ExxonMobil Chemical company (Houston, TX, USA), and plastomol (e.g., diisononyl adipate) from BASF (Florham Park, NJ, USA).

The curable composition optionally includes a flow control agent or thickener to provide the desired rheological properties to the composition. Suitable flow control agents include fumed silicas such as treated fumed silica available under the trade designation CAB-O-SIL TS 720 from Kabert Corporation (Alpharetta, GA, USA), and untreated fumed silica available under the trade designation CAB-O-SIL M5 from Cabot Corporation (Alpharetta, GA, USA).

In some embodiments, the curable composition optionally includes an adhesion promoter to enhance bonding to the substrate. The particular type of adhesion promoter may vary depending on the surface to which the composition is to be adhered. Adhesion promoters which have been found to be particularly useful for surfaces coated with ionic lubricants for promoting stretching of metal stock during processing include, for example, dihydroxyphenolic compounds such as catechol and thiodiphenol.

The curable composition optionally may further comprise one or more conventional additives such as fillers (e.g., aluminum powder, carbon black, glass bubbles, talc, clay, calcium carbonate, barium sulfate, titanium dioxide, silica such as fused silica, silicates, glass beads, and mica), flame retardants, antistatic materials, thermally and/or electrically conductive particles, and expansion agents, including, for example, chemical blowing agents such as azodicarbonamide or expandable polymeric microspheres containing liquid hydrocarbons, such as those sold under the trade name EXPANCEL by EXPANCEL Inc. The particulate filler may be in the form of flakes, rods, spheres, and the like. Additives are typically added in amounts to produce the desired effect in the resulting adhesive.

In another aspect, a cured composition is provided. The cured composition is the reaction product of the curable composition described above. That is, the cured composition comprises the reaction product (polymerization product) of a curable composition comprising an epoxy resin and composite particles mixed with the epoxy resin. The composite particles comprise 1) a porous polymeric core particle, 2) a curing agent and/or curing catalyst for the epoxy resin, the curing agent and/or curing catalyst positioned within the porous polymeric core particle but not chemically bonded to the porous polymeric core particle, and 3) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer. Any of the above curable compositions may be used to prepare the cured composition.

In yet another aspect, an article is provided that includes a cured composition positioned between a first substrate and a second substrate. The cured composition is formed from any of the curable compositions described above. The cured composition adheres to both the first substrate and the second substrate.

The cured composition is formed by the reaction (i.e., polymerization or curing) of the curable composition. In many embodiments, the curable composition is positioned between two substrates and then heated to diffuse the curing agent and/or curing catalyst from the composite particle. Upon diffusion from the composite particles, the curing agent and/or curing catalyst contacts the epoxy resin in the curable composition. If conditions are suitable for the reaction, a cured composition is formed. Suitable conditions for the reaction include, for example, having a concentration of curing agent and/or curing catalyst sufficient to mix with the epoxy resin and having a temperature sufficient to cure the epoxy resin.

The substrate may be selected from a variety of materials depending on the application. Materials that may be used for the substrate include, but are not limited to, metals, ceramics, glass, composites, polymeric materials, and the like. Metals that may be used as the substrate include, but are not limited to, aluminum and steel, such as high strength steel, stainless steel, galvanized steel, cold rolled steel, and surface treated metals. Surface treatments include, but are not limited to, paints, oil-based tensile or stamping lubricants, electroplating coatings, powder coatings, primers, chemical and physical surface treatments, and the like. Composites that may be used as substrates in the present disclosure include, but are not limited to, glass reinforced composites and carbon reinforced composites. Polymeric materials that may be used as substrates in the present disclosure include, but are not limited to, nylons, polycarbonates, polyesters, (meth) acrylate polymers and copolymers, acrylonitrile-butadiene-styrene copolymers, and the like.

In yet another aspect, a method of forming a cured composition is provided. The method includes providing a curable composition, heating the curable composition to release a curing agent and/or curing catalyst from the composite particle, and forming a cured composition by reacting the curing agent and/or curing catalyst with the epoxy resin. The curable composition is the same as described above and comprises an epoxy resin and composite particles mixed with the epoxy resin. The composite particles comprise 1) a porous polymeric core particle, 2) a curing agent and/or curing catalyst for the epoxy resin, the curing agent and/or curing catalyst positioned within the porous polymeric core particle but not chemically bonded to the porous polymeric core particle, and 3) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

The formation of composite particles comprising a curing agent and/or a curing catalyst allows for the preparation of one-component curable compositions. That is, all of the components of the curable composition can be mixed together and then heated for reaction (i.e., to form a cured composition). The curable composition may be stored for at least 1 day, at least 2 days, at least 3 days, at least 1 week, at least 2 weeks, at least 1 month, or longer prior to forming the cured composition. The curing time can generally be selected by controlling the temperature at which the curable composition is stored.

Various embodiments are provided that include composite particles, methods of making composite particles, curable compositions comprising an epoxy resin and composite particles, cured compositions comprising a polymerization product of the curable compositions, and articles comprising the cured compositions positioned between two substrates.

Embodiment 1A is a composite particle comprising a) a porous polymeric core particle, b) a curing agent and/or curing catalyst for an epoxy resin positioned within, but not covalently bound to, the porous polymeric core particle, and c) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

Embodiment 2A is the composite particle of embodiment 1A, wherein the porous polymeric core particle is a crosslinked (meth) acrylate polymeric material.

Embodiment 3A is the composite particle of embodiment 1A or 2A, wherein the porous polymeric core particle is a polymerization product of a first monomer composition comprising a monomer having at least two (meth) acryloyl groups.

Embodiment 4A is the composite particle of any one of embodiments 1A to 3A, wherein the first monomer composition comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 5A is the composite particle of any one of embodiments 1A to 4A, wherein the porous polymeric core particle comprises a polymerization product of a reaction mixture comprising I) a first phase and ii) a second phase dispersed in the first phase, wherein the second phase comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 6A is the composite particle of embodiment 5A, wherein the first phase comprises water and a polysaccharide dissolved in the water.

Embodiment 7A is the composite particle of embodiment 5A, wherein the first phase comprises a nonionic surfactant and a polyol compound of formula (II)

HO[-CH₂-CH(OH)-CH₂-O]_x-H

(II)

Wherein x is an integer equal to at least 1.

Embodiment 8A is the composite particle of any one of embodiments 5A to 7A, wherein the second phase further comprises poly (propylene glycol).

Embodiment 9A is the composite particle of embodiment 8A, wherein the poly (propylene glycol) has a weight average molecular weight of at least 500 daltons.

Embodiment 10A is the composite particle of embodiment 8A or 9A, wherein the poly (propylene glycol) is removed from the polymerization product to provide the porous polymeric core particle.

Embodiment 11A is the composite particle of any one of embodiments 1A to 10A, wherein the curing agent is of at least two formulas-NR⁷A compound of the group in which R⁷Is hydrogen, alkyl, aryl or alkaryl.

Embodiment 12A is the composite particle of embodiment 11A, wherein R⁷Is hydrogen or alkyl.

Embodiment 13A is the composite particle of any one of embodiments 1A to 10A, wherein the curing catalyst is an imidazole compound.

Embodiment 14A is the composite particle of any one of embodiments 1A to 10A, wherein the curing catalyst is a lewis acid.

Embodiment 15A is the composite particle of embodiment 14A, wherein the lewis acid comprises boron trifluoride, boron trichloride, zinc chloride, stannic chloride, antimony pentachloride, antimony pentafluoride, ferric chloride, aluminum trichloride, arsenic pentafluoride, or phosphorus pentafluoride.

Embodiment 16A is the composite particle of embodiment 15A, wherein the lewis acid is complexed with a hydroxyl-containing compound or a nitrogen-containing compound.

Embodiment 17A is the composite particle of any one of embodiments 1A to 16A, wherein the fluorinated polymer comprises a polymerization product of a second monomer composition comprising a fluorinated monomer having a (meth) acryloyl group.

Embodiment 18A is the composite particle of embodiment 17A, wherein the fluorinated monomer of formula (X)

Rf-Q-O-(CO)-CR¹＝CH₂

(X)

Wherein R is¹Is hydrogen or methyl, Rf is a fluorinated alkyl group, and Q is a divalent linking group. The group Q is not fluorinated. The group Rf may be partially or fully fluorinated.

Embodiment 19A is the composite particle of embodiment 18A, wherein Rf has 0 or 1 hydrogen atoms.

Embodiment 20A is the composite particle of embodiment 18A or 19A, wherein Q is

-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-、-(CH₂)_k-O-(CH₂)_k-、-(CH₂)_k-SO₂-(CH₂)_k-、-(CH₂)_k-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-S-(CH₂)_k-、-(CO)-NR¹¹-(CH₂)_k-、-CH₂CH(OR¹²)-CH₂-、-(CH₂)_k-SO₂-or-O- (CO) -NR¹¹-(CH₂)_k-. Radical R¹¹Is hydrogen, alkyl or aryl. Radical R¹²Is hydrogen or alkyl. The variable k is an integer in the range of 1 to 20.

Embodiment 21A is the composite particle of any one of embodiments 17A to 20A, wherein the monomer of formula (X) is of formula (X-1)

Rf-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-1)

Wherein Rf is a fluorinated alkaneRadical, R¹Is hydrogen or methyl, and k is an integer in the range of 1 to 20.

Embodiment 22A is the composite particle of any one of embodiments 18A to 20A, wherein the monomer of formula (X) is of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein Rf is a fluorinated alkyl group, R¹Is hydrogen or methyl, R¹²Is hydrogen, alkyl or aryl, and k is an integer in the range of 1 to 20.

Embodiment 23A is the composite particle of any one of embodiments 1A to 22A, wherein the composite particle comprises at least 20 wt.% porous polymeric core particle, at least 0.1 wt.% curing agent and/or curing catalyst, and at least 10 wt.% coating layer, based on the total weight of the composite particle.

Embodiment 24A is the composite particle of embodiment 23A, wherein the composite particle comprises 20 to 90 wt.% of the porous polymeric core particle, 1 to 70 wt.% of the curing agent and/or curing catalyst, and 10 to 80 wt.% of the coating layer.

Embodiment 25A is the composite particle of any one of embodiments 1A to 24A, wherein the coating has a thickness in a range of from 0.1 microns to 5 microns.

Embodiment 1B is a method of making a composite particle. The method includes providing a porous polymeric core particle. The method further comprises positioning a curing agent and/or a curing catalyst within the porous polymeric core particle to form a loaded porous polymeric core particle, wherein the curing agent and/or curing catalyst is not covalently bonded to the porous polymeric core particle. The method further includes providing a coating comprising a fluoropolymer surrounding the loaded porous polymeric core particle.

Embodiment 2B is the method of embodiment 1B, wherein providing the coating comprising fluoropolymer around the loaded porous polymer core particle comprises 1) forming a slurry comprising the loaded porous polymer core particle and a coating solution comprising the fluoropolymer and 2) spray drying the slurry.

Embodiment 3B is the method of embodiment 1B or 2B, wherein the coating solution comprises the fluoropolymer dissolved in a fluorinated solvent.

Embodiment 4B is the method of any one of embodiments 1B to 3B, wherein the porous polymeric core particle is a crosslinked (meth) acrylate polymeric material.

Embodiment 5B is the method of any one of embodiments 1B to 4B, wherein the porous polymeric core particles are a polymerization product of a first monomer composition comprising a monomer having at least two (meth) acryloyl groups.

Embodiment 6B is the method of embodiment 5B, wherein the first monomer composition comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 7B is the method of any one of embodiments 1B-6B, wherein providing the porous polymeric core particle comprises providing a polymerization product of a reaction mixture comprising I) a first phase and ii) a second phase dispersed in the first phase, wherein the second phase comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 8B is the method of embodiment 7B, wherein the first phase comprises water and a polysaccharide dissolved in the water.

Embodiment 9B is the method of embodiment 7B, wherein the first phase comprises a nonionic surfactant and a polyol compound of formula (II)

HO[-CH₂-CH(OH)-CH₂-O]_x-H

(II)

Wherein x is an integer equal to at least 1.

Embodiment 10B is the method of embodiment 7B, wherein the second phase further comprises poly (propylene glycol).

Embodiment 11B is the method of embodiment 10B, wherein the poly (propylene glycol) has a weight average molecular weight of at least 500 daltons.

Embodiment 12B is the method of embodiment 10B or 11B, wherein the poly (propylene glycol) is removed from the polymerization product to provide the porous polymeric core particle.

Embodiment 13B is the method of any one of embodiments 1B to 12B, wherein the curing agent is of at least two formulas-NR⁷A compound of the group in which R⁷Is hydrogen, alkyl, aryl or alkaryl.

Embodiment 14B is the method of embodiment 13B, wherein R⁷Is hydrogen or alkyl.

Embodiment 15B is the method of any one of embodiments 1B to 12B, wherein the curing catalyst is an imidazole compound.

Embodiment 16B is the method of any one of embodiments 1B to 12B, wherein the curing catalyst is a lewis acid.

Embodiment 17B is the method of embodiment 16B, wherein the lewis acid comprises boron trifluoride, boron trichloride, zinc chloride, stannic chloride, antimony pentachloride, antimony pentafluoride, ferric chloride, aluminum trichloride, arsenic pentafluoride, or phosphorus pentafluoride.

Embodiment 18B is the method of embodiment 17B, wherein the lewis acid is complexed with a hydroxyl-containing compound or a nitrogen-containing compound.

Embodiment 19B is the method of any of embodiments 1B to 18B, wherein the fluorinated polymer comprises a polymerization product of a second monomer composition comprising a fluorinated monomer having a (meth) acryloyl group.

Embodiment 20B is the method of any of embodiments 1B to 19B, wherein the fluorinated polymer comprises the polymerization product of a second monomer composition comprising a monomer of formula (X)

Rf-Q-O-(CO)-CR¹＝CH₂

(X)

Wherein R is¹Is hydrogen or methyl, Rf is a fluorinated alkyl group, and Q is a divalent linking group. The group Q is not fluorinated. The group Rf may be partially or fully fluorinated.

Embodiment 21B is the method of embodiment 20B, wherein Rf has 0 or 1 hydrogen atoms.

Embodiment 22B is the method of embodiment 20B or 21B, wherein Q is-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-、-(CH₂)_k-O-(CH₂)_k-、-(CH₂)_k-SO₂-(CH₂)_k-、-(CH₂)_k-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-S-(CH₂)_k-、-(CO)-NR¹¹-(CH₂)_k-、-CH₂CH(OR¹²)-CH₂-、-(CH₂)_k-SO₂-or-O- (CO) -NR¹¹-(CH₂)_k-. Radical R¹¹Is hydrogen, alkyl or aryl. Radical R¹²Is hydrogen or alkyl. The variable k is an integer in the range of 1 to 20.

Embodiment 23B is the method of embodiment 20B or 21B, wherein the monomer of formula (X) is of formula (X-1)

Rf-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-1)

Wherein Rf is a fluorinated alkyl group, R¹Is hydrogenOr methyl, and k is an integer ranging from 1 to 20.

Embodiment 24B is the method of embodiment 20B or 21B, wherein the monomer of formula (X) is of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein Rf is a fluorinated alkyl group, R¹Is hydrogen or methyl, R¹²Is hydrogen, alkyl or aryl, and k is an integer in the range of 1 to 20.

Embodiment 25B is the method of any one of embodiments 1B-24B, wherein the composite particle comprises at least 20 wt.% porous polymeric core particle, at least 0.1 wt.% curing agent and/or curing catalyst, and at least 10 wt.% coating layer, based on the total weight of the composite particle.

Embodiment 26B is the method of embodiment 25B, wherein the composite particle comprises 20 to 90 wt.% of the porous polymeric core particle, 1 to 70 wt.% of the curing agent and/or curing catalyst, and 10 to 80 wt.% of the coating layer.

Embodiment 27B is the method of any one of embodiments 1B to 26B, wherein the coating has a thickness in a range of 0.1 microns to 5 microns.

Embodiment 1C is a curable composition comprising (1) an epoxy resin and (2) composite particles admixed with the epoxy resin. The composite particles comprise (a) a porous polymeric core particle, (b) a curing agent and/or curing catalyst for an epoxy resin positioned within, but not covalently bound to, the porous polymeric core particle, and (c) a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer.

Embodiment 2C is the curable composition of embodiment 1C, wherein the porous polymeric core particle is a crosslinked (meth) acrylate polymeric material.

Embodiment 3C is the curable composition of embodiment 1C or 2C, wherein the porous polymeric core particles are a polymerization product of a first monomer composition comprising a monomer having at least two (meth) acryloyl groups.

Embodiment 4C is the curable composition of any one of embodiments 1C to 3C, wherein the first monomer composition comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 5C is the curable composition of any one of embodiments 1C to 4C, wherein the porous polymeric core particle comprises a polymerization product of a reaction mixture comprising I) a first phase and ii) a second phase dispersed in the first phase, wherein the second phase comprises a first monomer of formula (I)

CH₂＝C(R¹)-(CO)-O[-CH₂-CH₂-O]_q-(CO)-C(R¹)＝CH₂

(I)

Wherein q is an integer equal to at least 1, and R¹Is hydrogen or methyl.

Embodiment 6C is the curable composition of embodiment 5C, wherein the first phase comprises water and a polysaccharide dissolved in the water.

Embodiment 7C is the curable composition of embodiment 5C, wherein the first phase comprises a nonionic surfactant and a polyol compound of formula (II)

HO[-CH₂-CH(OH)-CH₂-O]_x-H

(II)

Wherein x is an integer equal to at least 1.

Embodiment 8C is the curable composition of any one of embodiments 5C to 7C, wherein the second phase further comprises poly (propylene glycol).

Embodiment 9C is the curable composition of embodiment 8C, wherein the poly (propylene glycol) has a weight average molecular weight of at least 500 daltons.

Embodiment 10C is the curable composition of embodiment 8C or 9C, wherein the poly (propylene glycol) is removed from the polymerization product to provide the porous polymeric core particle.

Embodiment 11C is the curable composition of any one of embodiments 1C to 10C, wherein the curing agent is of at least two formulas-NR⁷A compound of the group in which R⁷Is hydrogen, alkyl, aryl or alkaryl.

Embodiment 12C is the curable composition of embodiment 11C, wherein R⁷Is hydrogen or alkyl.

Embodiment 13C is the curable composition of any one of embodiments 1C to 10C, wherein the curing catalyst is an imidazole compound.

Embodiment 14C is the curable composition of any one of embodiments 1C to 10C, wherein the curing catalyst is a lewis acid.

Embodiment 15C is the curable composition of embodiment 14C, wherein the lewis acid comprises boron trifluoride, boron trichloride, zinc chloride, stannic chloride, antimony pentachloride, antimony pentafluoride, ferric chloride, aluminum trichloride, arsenic pentafluoride, or phosphorus pentafluoride.

Embodiment 16C is the curable composition of embodiment 15C, wherein the lewis acid is complexed with a hydroxyl-containing compound or a nitrogen-containing compound.

Embodiment 17C is the curable composition of any one of embodiments 1C to 16C, wherein the fluorinated polymer comprises a polymerization product of a second monomer composition comprising a fluorinated monomer having a (meth) acryloyl group.

Embodiment 18C is the curable composition of embodiment 17C, wherein the fluorinated polymer comprises a polymerization product of a second monomer composition comprising a monomer of formula (X)

Rf-Q-O-(CO)-CR¹＝CH₂

(X)

Wherein R is¹Is hydrogen or methyl, Rf is a fluorinated alkyl group, and Q is a divalent linking group. The group Q is not fluorinated. The group Rf may be partially or fully fluorinated.

Embodiment 19C is the curable composition of embodiment 18C, wherein Rf has 0 or 1 hydrogen atoms.

Embodiment 20C is the curable composition of embodiment 18C or 19C, wherein Q is

-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-、-(CH₂)_k-O-(CH₂)_k-、-(CH₂)_k-SO₂-(CH₂)_k-、-(CH₂)_k-SO₂-NR¹¹-(CH₂)_k-、-(CH₂)_k-S-(CH₂)_k-、-(CO)-NR¹¹-(CH₂)_k-、-CH₂CH(OR¹²)-CH₂-、-(CH₂)_k-SO₂-or-O- (CO) -NR¹¹-(CH₂)_k-. Radical R¹¹Is hydrogen, alkyl or aryl. Radical R¹²Is hydrogen or alkyl. The variable k is an integer in the range of 1 to 20.

Embodiment 21C is the curable composition of any one of embodiments 18C to 20C, wherein the monomer of formula (X) is of formula (X-1)

Rf-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-1)

Wherein Rf is a fluorinated alkyl group, R¹Is hydrogen or methyl, and k is an integer in the range of 1 to 20.

Embodiment 22C is the curable composition of any one of embodiments 18C to 20C, wherein the monomer of formula (X) is of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein Rf is a fluorinated alkyl group, R¹Is hydrogen or methyl, R¹²Is hydrogen, alkyl or aryl, and k is an integer in the range of 1 to 20.

Embodiment 23C is the curable composition of any one of embodiments 1C to 22C, wherein the composite particle comprises at least 20 wt.% of the porous polymeric core particle, at least 0.1 wt.% of the curing agent and/or curing catalyst, and at least 10 wt.% of the coating layer, based on the total weight of the composite particle.

Embodiment 24C is the curable composition of embodiment 23C, wherein the composite particle comprises 20 to 90 weight percent porous polymeric core particle, 1 to 70 weight percent curing agent and/or curing catalyst, and 10 to 80 weight percent coating layer.

Embodiment 25C is the curable composition of any one of embodiments 1C to 24C, wherein the coating has a thickness in a range from 0.1 microns to 5 microns.

Embodiment 1D is a cured composition that is the reaction product (i.e., the polymerization product) of any one of the curable compositions of embodiments 1C-25C.

Embodiment 1E is an article comprising a first substrate, a second substrate, and a cured composition positioned between the first substrate and the second substrate (i.e., the cured composition adheres to both the first substrate and the second substrate). The cured composition is a reaction product (i.e., a polymerized product) of any of the curable compositions of embodiments 1C through 25C.

Embodiment 1F is a method of forming a cured composition. The method includes providing the curable composition of any one of embodiments 1C to 25C, heating the curable composition to release the curing agent and/or curing catalyst from the composite particle, and curing the epoxy resin.

Examples

All chemicals used in the examples are available from the suppliers mentioned unless otherwise indicated.

Table 1: list of materials and suppliers

Test method

Differential scanning calorimetry

Differential Scanning Calorimetry (DSC) was performed on a TA Instruments (dela n-kasell) (TA Instruments Inc. (New Castle, Del.)) model Q2000. DSC samples were typically 6 mg to 20 mg. The test was performed in a sealed aluminum T-zero sample pan at a rate of 10 ℃/minute from room temperature (25 ℃) to 300 ℃. Data from the reaction process was plotted on a chart showing heat flow versus temperature. The integrated area under the exothermic peak represents the total exothermic energy generated during the reaction and is measured in joules/gram (J/g); the heat release energy is proportional to the degree of cure (i.e., degree of polymerization). The exotherm (i.e., the onset temperature (the temperature at which the reaction will begin to occur), peak temperature, and final temperature) provides information about the conditions required to cure the sample.

Shelf life test

The curable samples were left at room temperature under ambient conditions. The viscosity of the composition was monitored until the mixture could not be stirred by hand.

Curing time test

The curable sample (10 grams) was placed in an oven at the selected temperature (recorded when results are reported below). The cure time is the amount of time required for the liquid adhesive to reach a maximum viscosity or modulus.

Lap shear strength (OLS)

The lap shear strength of each adhesive film formulation was measured by bonding 25mm x 100mm x 1.6mm steel coupons into test specimens as described in ASTM 1002-01. The steel coupons used to measure shear strength were cold rolled steel (available under the trade designation "Q-PANEL, RS-14" from Q-Lab corporation of Westlade, Ohio, Q-Lab Corp., Westlake, OH, USA)). Steel coupons were prepared by scrubbing the steel coupons with acetone and allowing them to air dry for five minutes. The adhesive was applied by using 10 mil (about 254 microns or 0.010 inches) glass beads as spacers and two steel coupons were mated together (total thickness of adhesive film was about 250 microns) and then clamped in place using a disposable binder clip. Upon curing, the jig was removed. The lap shear specimen was clamped to a jaw of a tensile testing machine (model INSTRON 5581, equipped with a 10,000 pound (about 4536 kilogram) load cell) and the specimen was pulled apart at a collet speed of 12.5 millimeters (mm) per minute until the bond failed. The results are reported in megapascals (MPa).

Preparation example 1: synthetic porous polymer core particles

Monomers SR339 (50 g), SR6030P (50 g) and sulfoethyl methacrylate (5 g) were mixed with PPG 4000(43 g) and IRGACURE 819(0.25 g). The mixture was stirred vigorously for 20 minutes with mild heating at about 40 ℃ to 50 ℃. This mixture was then added to 300 grams of glycerin previously mixed with the surfactant APG 325N (15 grams). The mixture was shear stirred for 20 minutes. The mixture was then spread between two pieces of polyethylene terephthalate (PET) and cured with uv light for 10 to 15 minutes using a 100 watt long wave BLACK RAY uv lamp (obtained from UVP, LLC of Upland, CA, USA) located about 15 centimeters (6 inches) from the surface of the cured material.

The solidified mixture was then dispersed in excess water (500mL), shaken for 30 minutes, and centrifuged at 3000rpm in an EPPENDORF 5810R centrifuge (EPPENDORF in germany). The supernatant was removed and the resulting particles were then resuspended in 500mL of water for a second wash, followed by centrifugation. Thereafter, the particles were suspended in 500mL of isopropanol and shaken for 20 minutes. This extracts the PPG 4000 and leaves voids (i.e., pores or free volume) in the particles. The particles were then centrifuged at 300 revolutions per minute (rpm) for 30 minutes and the supernatant discarded. The particles were oven dried at 70 ℃ overnight to eliminate any remaining isopropanol in the mixture.

Fig. 1A and 1B are scanning electron micrographs at different magnifications of the formed porous polymeric core particles.

Preparation example 2: preparation of heptafluorobutyl methacrylate ("FBMA"; prepared according to the method described in WO 2002/016517(Savu et al) for fluorocopolymer 1):

FBMA was prepared as follows. 1260g of heptafluorobutanol, 20g of 95% sulfuric acid, 1.2g of phenothiazine and 1g of 4-Methoxyphenol (MEHQ) were placed in a 3-liter flask equipped with an overhead stirrer, thermocouple and addition funnel. The reaction mixture was heated to 55 ℃ and 946g of methacrylic anhydride were then started to be added. The reaction mixture was allowed to exotherm to 65 ℃ and the rate of addition was adjusted to maintain the reaction mixture temperature at 65 ℃. The addition of methacrylic anhydride was completed within 2.5 hours. The reaction mixture was heated at 65 ℃ for an additional 3 hours and then allowed to cool to room temperature. 1200mL of deionized water was added and the resulting reaction mixture was stirred for 30 minutes. The mixture was allowed to phase separate and the translucent purple fluorochemical lower phase was preserved. The lower phase is then stirred for 30 minutes with a mixture of 416g of sodium carbonate, 50g of sodium hydroxide and 1500g of water. Again, the mixture was phase separated and the lower fluorochemical phase was preserved and washed twice with 1500g aliquots of water to give 1531g crude FBMA. To a 3 liter flask equipped with a distillation head and thermocouple was added the crude methacrylate. More polymerization inhibitor (3g phenothiazine and 0.7g MEHQ) was added to the distillation flask. The acrylate was distilled and 138g of the predistillation was distilled off at 176 torr at a top temperature of 61 ℃ to 79 ℃. The pre-distillate was then distilled at 79 ℃ to 85 ℃ and 161 torr (21.5kPa) to give a total of 1274g of purified FBMA.

Preparation ofExample 3: preparation of Poly (FBMA)

Poly (FMBA) was prepared from FBMA according to the procedure described in WO 2002/016517(Savu et al) for making fluorocopolymer 1, except that acrylic acid was not included. The polymer had a number average molecular weight of 50,000 daltons and a weight average molecular weight of 70,000 daltons.

Preparation example 4: preparation of Poly (FBMA/acrylic acid) (98:2) ("Poly (FBMA/AA)")

Poly (FMBA/AA) was prepared according to the procedure described in WO 2002/016517(Savu et al) for making fluorocopolymer 1, except that the ratio of FBMA to acrylic acid was 98: 2. The weight average molecular weight was about 28,000Da and the number average molecular weight was about 17,000 Da. Poly (FBMA/AA) was used as a 17.8 wt.% solids solution in NOVEC 7100.

Preparation example 5: preparation of N-methylperfluorobutanesulfonamido ethyl methacrylate ("MeFBSEMA")

Preparation of MeFBSEMA is similar to that of the acrylate analog MeFBSEA of example 2.B of U.S. Pat. No. 6,664,354(Savu et al).

Preparation example 6: preparation of Poly (MeFBSEA)

Poly (MeFBSEMA) was prepared similarly to the preparation of fluorocopolymer 1 in WO 2002/016517(Savu et al) except that acrylic acid was not included. The polymer had a number average molecular weight of 30,000 daltons and a weight average molecular weight of 45,000 daltons.

Examples 1 to 5: preparation of composite particles

Example 1(EX-1)

50 grams of the porous polymeric core particle of preparative example 1 was mixed with 25 grams of 1, 2-dimethylimidazole (12DMZ) at 40 ℃ for 5 minutes at ambient conditions. The mixture was then cooled to room temperature. All 12DMZ was adsorbed by the porous polymer core particle.

Next, 12 DMZ-filled porous polymeric core particles were added to a solution of 100 grams of poly (FBMA) in 600 grams of NOVEC 7100 solvent. The suspension was further mixed with an ultrasonic probe. The suspension (i.e., slurry) was Spray dried using a custom 48-mix flow Spray dryer manufactured by Spray Drying Systems, Inc (head dried in Eldersburg, MD), available from Spray Drying Systems limited.

The spray dryer was 4 feet (1.2 meters) in diameter and had 8 feet (2.4 meters) straight sides. The spray dryer was operated in a closed loop mode (the system was purged with nitrogen which was then circulated as a bulk drying gas during operation). During operation, this large volume of drying gas is heated via an electric heater and passed through a drying chamber (entering through the top and exiting through the bottom) and finally to a cyclone and baghouse, then through a blower (a 1 horsepower dryer available from air technology corporation of Englewood, NJ) and a condenser (to condense out the solvent), and then returned to the heater for reuse. The cyclone separates the product solids from the gas stream; the solids collected in the baghouse were discarded. The bulk drying gas temperature at the inlet of the drying chamber was 67 ℃ to 69 ℃ and the outlet of the drying chamber was 49 ℃. Slurry was supplied at about 45 grams/minute by a pneumatic peristaltic pump using a single mass flow line 96420-16 platinum cured silicone. The slurry was atomized vertically upward using an internally mixed two-FLUID pressure spray atomizing nozzle (commercially available from Spraying Systems Co., Wheaton, illinois) under the trade designation "fluuid CAP 60100" and "AIR CAP 170. the atomizing gas was nitrogen, supplied at 12psi (0.08MPa) and 3.5 (+ -0.05) standard cubic feet per minute (about 99.1 standard liters per minute).

The resulting composite particles (capsules) contained the calculated 14 wt% 12DMZ catalyst and the calculated 1.63 micron fluoropolymer (poly (FBMA)) shell surrounding the porous polymer core particles.

Example 2(EX-2)

50 grams of the porous polymeric core particle of preparative example 1 was mixed with 25 grams of 1-benzyl 2-methylimidazole (1B2MZ) at room temperature under ambient conditions. All of 1B2MZ was adsorbed by the porous polymeric core particle within five minutes.

Next, 1B2 MZ-loaded porous polymeric core particles were mixed with 375 grams of the poly (FBMA)/AA solution of preparative example 4 (with 17.8 wt% solids) and with 200 grams of NOVEC 7200 solvent. The suspension was further mixed with an ultrasonic probe. The resulting slurry was spray dried as in example 1, except that: (1) the chamber inlet temperature was 66 deg.C, (2) the outlet temperature was 48 deg.C, (3) the slurry was provided at 48 (+ -7) grams per minute, and (4) the atomized nitrogen was provided at 10psi (0.07MPa) and 3.40 (+ -0.05) standard cubic feet per minute (about 96.3 standard liters per minute).

The resulting composite particles (capsules) contained a calculated 17 wt% of 1B2MZ catalyst and a calculated 1.26 micron shell of fluoropolymer (fluorinated poly (acrylate)) surrounding the porous polymeric core particles.

Example 3(EX-3)

50g of the porous polymer core particles of preparation 1 were admixed with 25 g of SbF₅DEG was mixed at 40 ℃ for 5 minutes at ambient conditions. The mixture was then cooled to room temperature. All SbF₅DEG is adsorbed by the porous polymer core particle.

Next, the SbF will be loaded₅The porous polymer core particles of DEG were mixed with 375 grams of poly (FBMA)/AA solution of preparative example 4 (with 17.8 wt% solids) and with 200 grams of NOVEC 7200 solvent. The suspension was further mixed with an ultrasonic probe. The resulting slurry was spray dried as in example 1, except that: (1) the chamber inlet temperature is 71 ℃ to 73 ℃, (1) the outlet temperature is 47 ℃, (3) the slurry is provided at about 55 grams per minute, and (4) the atomized nitrogen is provided at 10.5psi (0.07MPa) and 3.55(± 0.05) standard cubic feet per minute (about 100.5 standard liters per minute).

The resulting composite particles (capsules) contained a calculated weight percent of SbF of 17₅DEG catalyst and a calculated fluoropolymer (fluorinated poly (acrylate)) shell of 1.26 microns surrounding the porous polymer core particle. Fig. 2 is a scanning electron micrograph of the formed composite particles.

Example 4(EX-4)

50g of the porous polymer core particles of preparation 1 were admixed with 25 g of SbF₅DEG was mixed at 40 ℃ for 5 minutes at ambient conditions. The mixture was then cooled to room temperature.All SbF₅DEG is adsorbed by the porous polymer core particle.

Next, the SbF will be loaded₅The porous polymer core particles of DEG were mixed with 750 g of the poly (FBMA)/AA solution of preparative example 4 (with 17.8 wt% solids) and 300 g of NOVEC 7100 solvent. The suspension was further mixed with an ultrasonic probe. The resulting slurry was spray dried as in example 1, except that: (1) the chamber inlet temperature is 59 ℃ to 61 ℃, (2) the outlet temperature is 43 ℃, (3) the slurry is provided at 55 grams per minute, and (4) the atomized nitrogen is provided at 10psi (0.07MPa) and 3.40(± 0.05) standard cubic feet per minute (about 96.3 standard liters per minute).

The resulting composite particles (capsules) contained a calculated 11 wt% SbF₅DEG catalyst and a calculated fluoropolymer shell of 2.3 microns surrounding the porous polymer core particles. Fig. 3 is a scanning electron micrograph of the formed composite particles.

Example 5(EX-5)

50 grams of the porous polymeric core particles of preparative example 1 were mixed with 25 grams of LEECURE B614 at 40 ℃ for 5 minutes at ambient conditions. The mixture was then cooled to room temperature. All LEECURE B614 was adsorbed by the porous polymer core particles.

Next, the porous polymer core particles loaded with LEECURE B614 were added to a solution of 150 grams poly (MeFBSEMA) in 900 grams NOVEC 7200 solvent. The suspension was further mixed with an ultrasonic probe. The resulting slurry was spray dried as in example 1, except that: (1) the chamber inlet is 62 ℃ to 64 ℃, (2) the outlet temperature is 46 ℃, (3) the slurry is provided at 23(± 3) grams/minute, and (4) the atomized nitrogen is provided at 13psi (0.09MPa) and 3.95(± 0.05) standard cubic feet per minute (about 111.9 standard liters/minute).

The resulting composite particles (capsules) contained a calculated 11 wt% LEECURE B614 catalyst and a calculated 2.3 micron fluoropolymer shell.

Example 6(EX-6)

50 grams of the porous polymeric core particles of preparative example 1 were mixed with 25 grams of LEECURE B614 at 40 ℃ for 5 minutes at ambient conditions. The mixture was then cooled to room temperature. All LEECURE B610 was adsorbed by the porous polymer core particles.

Next, the porous polymer core particles loaded with LEECURE B610 were added to a solution of 150 grams of poly (MeFBSEMA) in 900 grams of NOVEC 7100 solvent. The suspension was further mixed with an ultrasonic probe. The resulting slurry was spray dried as in example 1, except that: (1) the chamber inlet temperature is 60 ℃ to 62 ℃, (2) the outlet temperature is 44 ℃ to 45 ℃, (3) the slurry is provided at 32 grams per minute, and (4) the atomized nitrogen is provided at 12psi (0.08MPa) and 3.6(± 0.05) standard cubic feet per minute (about 101.9 standard liters per minute).

The resulting composite particles (capsules) contained the calculated 11 wt% LEECURE B610 catalyst and the calculated 2.3 micron fluoropolymer shell.

Examples 7 to 12: one-component, heat-curable composition comprising composite particles

Example 7(EX-7)

A one-part, heat-curable composition was prepared by placing 8.6 grams of EPON 828 and 1.4 grams of example 1, example 1 containing 14 wt% of the encapsulated 12DMZ catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. The samples were mixed with a DAC mixer (SpeedMixer DAC 150.1FV from flalctek, Inc.) for 1 minute at 1000 RPM. The samples were then weighed into Differential Scanning Calorimetry (DSC) pans for analysis. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 130 ℃) and the shelf life at 25 ℃ (using the shelf life test described above).

Example 8(EX-8)

A one-part, heat-curable composition was prepared by placing 8.8 grams of EPON 828 and 1.2 grams of example 2, example 2 containing 17 wt% of the encapsulated 1B2MZ catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. Table 2 contains the onset and peak temperatures from the DSC scans, which were obtained as described above. Table 2 also includes cure time data (using the cure time test described above at 100 ℃) and shelf life at 25 ℃ (using the shelf life test described above).

Example 9(EX-9)

A one-part, heat-curable composition was prepared by placing 8.8 grams of EPON 828 and 1.2 grams of example 3, example 3 containing 17 wt% encapsulated 17% SbF₅-DEG catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 80 ℃) and the shelf life at 25 ℃ (using the shelf life test described above). The DSC scan of example 9 was compared to the DSC scan of comparative example 1 in figure 4.

Example 10(EX-10)

A one-part, heat-curable composition was prepared by placing 8.2 grams of EPON 828 and 1.8 grams of example 4, example 4 containing 11 wt% encapsulated SbF₅-DEG catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 100 ℃) and the shelf life at 25 ℃ (using the shelf life test described above). The lap shear of example 10 was compared with the lap shear of comparative example 1 in fig. 3.

Example 11(EX-11)

A one-part, heat-curable composition was prepared by placing 73 parts EPON 828 and 27 parts example 5, example 5 containing 11 wt% encapsulated LEECURE B614 catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 120 ℃) and the shelf life at 25 ℃ (using the shelf life test described above).

Example 12(EX-12)

A one-part, heat-curable composition was prepared by placing 73 parts EPON 828 and 27 parts example 6, example 6 containing 11 wt% encapsulated LEECURE B610 catalyst. The catalyst was used in an amount of 2% by weight based on the entire curable composition. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 120 ℃) and the shelf life at 25 ℃ (using the shelf life test described above).

Comparative examples 1 to 3

Comparative example 1(CE-1)

By combining 98 parts by weight of EPON 828 with 2 parts of SbF₅DEG catalyst (the catalyst is not encapsulated) was mixed to prepare comparative example (CE-1). Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 50 ℃) and the shelf life at 25 ℃ (using the shelf life test described above). The lap shear of comparative example 1 was compared with that of example 10 in table 3. The DSC scan of comparative example 1 was compared to the DSC scan of example 9 in figure 4.

Comparative example 2(CE-2)

A comparative example (CE-2) was prepared by combining 98 parts by weight of EPON 828 with 2 parts of LEECURE B614 catalyst, which was not encapsulated. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 65 ℃) and the shelf life at 25 ℃ (using the shelf life test described above).

Comparative example 3(CE-3)

A comparative example (CE-3) was prepared by combining 98 parts by weight of EPON 828 with 2 parts of LEECURE B610 catalyst, which was not encapsulated. Table 2 contains the onset and peak temperatures from the DSC scan, which were obtained as described above, and table 2 also includes the cure time data (using the cure time test described above at 65 ℃) and the shelf life at 25 ℃ (using the shelf life test described above).

Table 2: curing of examples 7-12 and comparative examples 1-3

Lap Shear (OLS) specimens of EX-10 and CE-1 were prepared on a cold rolled stainless steel substrate and allowed to cure at 80 ℃ for 30 minutes. EX-10 and CE-1 each contained 2% by weight of SbF in the curable composition₅-DEG catalyst. Details of the lap shear test are further described above. The results are shown in Table 3. Encapsulation of the catalyst within the composite particles having a fluoropolymer shell has no adverse effect on the OLS compared to unencapsulated systems. In addition, the OLS did not decrease after aging the specimens at 80 ℃ for 5 days and 10 days.

Table 3: lap shear of EX-10 and CE-1。

Claims (6)

1. A composite particle, comprising:

a)20 to 90 weight percent of a porous polymeric core particle comprising a crosslinked (meth) acrylate polymeric material;

b)1 to 70 weight percent of a curing agent and/or curing catalyst for an epoxy resin positioned within, but not covalently bound to, the porous polymeric core particles; and

c)10 to 80 weight percent of a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer comprising the polymerization product of a monomer composition comprising a monomer of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein

Rf is a fluorinated alkyl group;

R¹is hydrogen or methyl;

R¹²is hydrogen, alkyl or aryl; and is

k is an integer in the range of 1 to 20.

2. The composite particle of claim 1, wherein the composite particle comprises a curing catalyst that is a lewis acid.

3. A curable composition comprising:

a) an epoxy resin; and

b) composite particles mixed with the epoxy resin, wherein the composite particles comprise

i)20 to 90 weight percent of a porous polymeric core particle comprising a crosslinked (meth) acrylate polymeric material;

ii)1 to 70 weight percent of a curing agent and/or curing catalyst for epoxy resins positioned within, but not covalently bound to, the porous polymeric core particles; and

iii)10 to 80 weight percent of a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer comprising the polymerization product of a monomer composition comprising a monomer of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein

Rf is a fluorinated alkyl group;

R¹is hydrogen or methyl;

R¹²is hydrogen, alkyl or aryl; and is

k is an integer in the range of 1 to 20.

4. The curable composition of claim 3, wherein the composite particles comprise a curing catalyst that is a Lewis acid.

5. A cured composition comprising the reaction product of a curable composition comprising:

a) an epoxy resin; and

b) composite particles mixed with the epoxy resin, wherein the composite particles comprise

i)20 to 90 weight percent of a porous polymeric core particle comprising a crosslinked (meth) acrylate polymeric material;

ii)1 to 70 weight percent of a curing agent and/or curing catalyst for epoxy resins positioned within, but not covalently bound to, the porous polymeric core particles; and

iii)10 to 80 weight percent of a coating layer surrounding the porous polymeric core particle, wherein the coating layer comprises a fluorinated polymer comprising the polymerization product of a monomer composition comprising a monomer of formula (X-2)

Rf-SO₂-NR¹²-(CH₂)_k-O-(CO)-CR¹＝CH₂

(X-2)

Wherein

Rf is a fluorinated alkyl group;

R¹is hydrogen or methyl;

R¹²is hydrogen, alkyl or aryl; and is

k is an integer in the range of 1 to 20.

6. The cured composition of claim 5, wherein the curing catalyst is a Lewis acid.

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